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Technical article
Fuse, fuse resistor to prevent burnout or fire of semiconductor components
Current Fuses and Fusing ResistorsHow To Use Current Fuses and Fusing ResistorsCurrent Fuses are one of the simplest devices to protect a circuit. The resistors with fusing function protect the equipment or parts from burning by breaking the abnormal current in a malfunction such as short-circuiting. TF, CCP , and CCF are lined up.This product also has the fusing function. It works to fuse and prevent semiconductor element or resistor from burning or firing when the current exceeding fusing power is dissipated.TF Chip fusesCharacteristicsIt is a small, lightweight chip current fuse for secondary circuits.According to the exclusive structure and production method, the fuse characteristics are stable.Can reduce the occupied area.Low internal resistance and reduced voltage can reduce power consumption.Overcurrent protection for circuit components for small electronic devices.Corresponding to reflow soldering and wave soldering.Conforms to EU RoHS. CCP Circuit protection componentCharacteristicsWhen the current is too large, the circuit can be cut off quickly, smokelessly and without heat.The metal electrode is used, the terminal strength is excellent, and the solder adhesion is excellent.The exterior molding is molded, the dimensional accuracy is high, and the mounting performance is excellent.Terminal lead-free products, in line with EU RoHS.Corresponding to reflow and wave soldering CCF Chip current fuse (anti-vulcanization type)CharacteristicsExcellent resistance to vulcanization due to the use of high-performance anti-vulcanization materials.According to IEC60127-4. (7A or less)It is made of ceramic body and has excellent mechanical strength.Corresponding to reflow and wave soldering.Conforms to EU RoHS.Fusing resistors are suitable where certain resistance is required for using a circuit and a failure of any other device might cause smoke or fire. In general, blow speed is slower than that of current fuse, it will not be recommended for instantaneous fusing requirement. Check fusing resistor lineup of leaded resistors for RF73 RF RF26 RF25CC and WF.Current FusesFusing ResistorsNormal functionZero current pathSpecified value resistorOverloadBlowBlowCause of blowOver currentOver power dissipationFusing CharacteristicsInstantaneous fusingPrecise fusinSlow blowWide scatter in fusingApplication Examples of Current FusesOne piece of the fusing product is enough as long as the fuse of the main power supply is fused when any local failure of power circuit is caused. But the power supply of today's equipment is divided into several independent blocks and the main power supply unit sometimes fails to detect the malfunction in terminal where current is small. A failure, severe enough to cause a danger in the local block, might not always be detected at the main fuse.To design a safe circuit, we recommend fuses or some protective devices should be included in each branch or block so circuits shall not emit smoke or catch fire even if a malfunction like short-circuit or motor lock is caused in each block.Diagram of TF structureDiagram of CCP structure Diagram of CCF structure  Application Example of Fusing ResistorsIn the IC circuit recommended, a resistor is inserted in to the power supply Vcc in series, it works as a current limiter, and at the same time as a decoupling device with noise together with the capacitor.But in case of failure, when the IC or the capacitor is short circuited, depending on the supply voltage and resistance value, the resistor may emit smoke or catch fire without operating any protector circuit. Fusing Resistors RF RF73 are suited to break the current without burning. RF Coated insulated fuse resistorCharacteristicsUsually functions as a resistor.For abnormal overload, quickly blow and protect the circuit.Flame retardant coating (equivalent to UL94 V-0).Conforms to EU RoHS.  RF73 Rectangular chip fuse resistorCharacteristicsIt functions as a resistor during use, and it quickly breaks when it is abnormal to prevent damage to the circuit.It is the same shape as the R73 series.It is UL1412 safety standard certification product (1J is not recognized).Corresponding to reflow soldering and wave soldering.Terminal lead-free products, in line with EU RoHS. Lead glass contained in electrodes, resistive layers, and glass is not applicable to the EU RoHS Directive Resistors to suppress parasitic oscillation of emitter follower circuitEmitter follower circuits are often used to realize low output impedance amplifiers. But they can oscillate parasitically unless proper attention is paid. When this phenomenon is overlooked, unexpected trouble may be caused, e.g. EMI. Moreover, it is difficult to check oscillation because the condition is so delicate as to be changed by touching with a probe of an oscilloscope. Still more, oscillation can be stopped even with changing temperatures.An effective solution for this kind of oscillation will be to decouple the collector from the Vcc and to put a resistor Rb, ranging from several 10 to several 100, to the base circuit as illustrated. When the emitter load is capacitive, inserting a low resistance resistor into the load in series also has an effect.For power amplifiers, this series resistance becomes very small. And it might bring about unexpected heating or going up in smoke depending on the transistor failure mode. In such situations, Fusing Resistors RF or RF73 which has a fuse function is recommended. Rush current should be taken into consideration together when choosing Fusing Resistors.Resistors to stabilize FET switching operationMOSFET is popular high frequency switching device. A gate resistor of a low value has an effect of stabilizing switching operation. If resistance is too low, it may give instability due to chattering at transistor "on" and "off" transient. On the other hand, the waveform becomes dull if gate resistance is too high. Therefore the suitable value should be determined by observing the waveform. This consideration is especially important for power MOS devices, because the gate resistance may have correlation to surge voltage and switching energy loss.For power MOSFET, this gate resistance becomes very small. And it brings unexpected heat and emission of smoke due to the transistor failure mode. In such situations, Fusing Resistors RF or RF73 which has a fuse function is recommended. Rush current should be taken into account together when choosing Fusing Resistors.4242.com
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Inductors are classified according to winding structure and core material.
Types and characteristics of inductorsThere are many kinds of inductors, some of which are called by function, such as "anti-current coil" and "ignition coil" etc. Some are expressed by shape like "chip inductor". An inductor will have many names depending on its usage, which can easily cause confusion.Next, we will introduce inductors from different pointcuts.Classification based on winding structureWound inductor                                                          About coils, the most familiar thing is spring inductors.                                                                      照片-1 Spring inductor Such an inductor is basically a copper wire with an insulating film, that is, a magnetic wire, a coil-like spring-like spiral shape, a type wound around a plastic bobbin, and a type directly wound around a molded ferrite core.(Fig. 7)Fi-8 Rectangular magnetic wire effectIn order to meet the demand for miniaturization and thinning, such inductors have developed many kinds of winding structures. There is no shortage of types that use rectangular magnet lines instead of circles. (Fig. 8) In this way, the gap of the winding portion is eliminated. When the number of turns is the same, the cross-sectional area of the copper wire is increased, the DC resistance is reduced, and the copper loss is also reduced. This makes it possible to produce a highly efficient inductor.For the same reason, the use of copper plates instead of magnetic wires has also been put into practical use.Laminated inductorCompared with energy efficiency, inductors for high-frequency circuits pay more attention to miniaturization and high-frequency characteristics. Nowadays, the idea of discarding "winding" has appeared, and conductors of conductor metal are printed on the sheets and substrates.A fraction of a circle of inductor is printed on a green sheet that is stretched into flakes from ferrite and ceramic materials. Overlapping multiple layers is the inductor. With the thinning of green sheets, fine printing techniques, and advances in the technology of using via-holes, it is possible to fabricate small, high-inductance inductors. (Fig.9)Fig-9 Laminated inductor Thin film inductorCorresponding to a laminated inductor printed by a screen printing method, an inductor having a coil pattern is formed by using a metal film having a thinner printing than a printing method using a sputtering degree and an evaporation technique, and is called a thin film inductor. Provides small, high-precision inductors through the use of semiconductor manufacturing technology. (Fig. 10)Fig-10 Thin film inductor Classified according to placementThere are lead type inductors for surface mount and surface mount type (chip inductors). According to the core material classification Silicon steel plateMaterials that are good at use in the low frequency band are widely used in power transformers, choke coils, etc. in the commercial frequency band (50/60 Hz). Adding a few percent of iron to iron can increase magnetic permeability and reduce aging. This material is cold-rolled to form a plate having a thickness of about 0.05 to 0.5 mm, and then pressed into an E-type I, and then several tens of sheets are used in an overlapping manner.In order to prevent the loss caused by the eddy current, the surface of the core should be insulated one by one. The higher the frequency, the thinner the steel plate used.PermalloyA high magnetic permeability material made of nickel added to iron is called permalloy. By adjusting the nickel content, the initial magnetic permeability and the saturation magnetic flux density change, and thus it is suitable for a low-frequency signal transformer, a choke coil, and the like.Powder coreIt is pressed from a fine particle powder containing molybdenum as a main component, and its magnetic resistance is higher than that of a bismuth steel plate, so that the loss due to eddy current can be reduced. Suitable for high-frequency smoothing coils of power line filters and switching power supplies.Ferrite coreWide range of high permeability materials for high frequency applications. The main component, iron oxide (Fe2O2), is mixed with a metal compound such as manganese, magnesium, nickel, zinc, etc., and is sintered at a high temperature. Representative ferrites include Mn-Zns and Ni-Zns.Air coreAn inductor that does not use a magnet as a core material is called a hollow inductor. The core material is hollow (air), and the core material is a wound inductor using a non-magnetic material such as alumina, a laminated inductor in which a non-magnetic material sheet is stacked, a thin film inductor using a non-magnetic material substrate, etc., all of which are hollow inductors. Device. It is called a hollow inductor because there is no such thing as a magnet core (= empty). 4242.com
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Classification of resistance according to structure and usage
Categorize by ConstructionCategory of ResistorsThere are various types of resistors if you combine function, shape, resistive material and its purposes.Categorized by function, there are three types of resistors; relative resistors, used in a electric circuit; trimmer potentiometer to adjust a circuit; variable resistor, used as a radio volume by changing the resistance.relative resistors are divided into lead type(with lead wire) and surface mount type without lead wire. Surface mount type includes rectangular type and cylinder type. Resistors are more divided into resin mold type and ceramic type, etc depending on cealing material.   The materials of resistive body includes more; Film type that includes carbon film, metal film that applies Nicrom, metal oxide film and metal glaze composited by metal oxide and glass; metal plate, metal wire, those that apply metal foil; solid type that applies metal oxide ceramics.          The purposes of resistor are different depending on resistance tolerance, temperature characteristics, high voltage type, surge resistant type, fusing type and temperature characteristic that changes resistance. You have to select a suitable resistor for your purpose depending on combinations mentioned above. Characteristics of relative resistorsrelative Chip ResistorResistors with the electrodes are processed for both soldering and bonding or either of them. These types of resistors do not have terminal wire(lead wire).They are divided into rectangular type and cylindrical type. There are five following types according to resistive material.Rectangular type——1. Metal glaze film type, 2. Metal film type, 3. Metal plate typeCylindrical type——3. Carbon film type, 4. Metal film typeAmong them, metal glaze film type consists mostly of the market considering cost, downsizing and mountability. Some statistics say that more than 90% of relative chip resistors are metal glaze film type. The trend of downsizing is increasing amont this type of resistors; size 1005(1.0mm×0.5mm) or size 0603(0.6mm×0.3mm) are increasing, whereas mobile telecommunication field like cell phones and smartphones are applying size 0402(0.4mm×0.2mm).Rectangular type chip relativeresistorsThis type is largely divided into thick film metal glaze type and thin film metal type. Thick film type is mostly massproduced. Thick film type is excellent for mountability and environmental resistance whereas thin film type features small resistance tolerance, small T.C.R. and low current noise. Especially for TC.R., thick film type is around 100×10-6/K while thin film type has extremely small T.C.R. like 10×10-6/K and achieves stable resistance. The size of rectangular type resistors are specified from 0402, 0603, 1005. 1608, 2012 and 3216. The size 0603 are rapidly increasing among mobile telecommunication devices. Size 1005 and 1608 are applied mainly for consumer products, size 1608 and 2012 are widely used for consumer products, industrial equipment and automotive applications. High power type has size 3216, 3225, 5025 and 6331 in its portfolio.Cylindrical chip relative resistorThis is so called MELF type resistors which has such construction of general type axial lead resistors without lead wire but with metal plate cap on both ends of the body instead.  The product features cylindrical shape with metal caps, so no two sides, excellent electrode strength and mechanical strength, excellent dimension tolerance and suppy and mountability. Metal film type also features to achieve resistance precision, T.C.R. and current noise in high level.Network resistorsTwo or more resistive elements are integrated and compound on a insulative substrate and this resistor circuit network is regarded as one electronic component. Each one can be connected as necessary. If this is integrated by resistors with two electrodes each, we call it alley, whereas we call network for those integrated by forming a circuit network.The main applications are pull-up and pull-down resistors for digital circuits.They are divided into SIP(Single Inline Package)type, DIP(Dual Inline Package)type, flat package type, chip carrier type.In the past when the carbon film resistors were the mainstream, output of SIP type had been rapidly increasing to meat high density mounting. As the mounting technology changed into surface mount type, products shifted to chip network resistors and the current mainstream is chip network resistors and SOP(Small Outline Package) type.Chip network resistors covers to response the high density mounting by chip resistors, which shows the largest growth in the output among network resistors. two-alley and four-alley are the mainstream of the demand, size 3216 is used for industrial equipment, size 1608 for electronic devices, size 1005 and 0603 for cell phones, computers, DSC, digital video cameras.Carbon film relative resistorsrelative resistors that have carbon film as a resistive element, which is the most popular type resistors from long ago. 1/4W type and 1/2W type are the most by electric category; now the small type like 1/4W type in size 3.2mm×φ1.9mm and 1/2W type in size 6.3mm×φ2.85mm are the mainstream and excellent in pulse resistance. They are widely used as general-purpose type.Metal film relative resistorsrelative resistors that have metal film as a resistive element, which are high precision and stable, with small resistance tolerance, T.C.R. and aging. Low current noise, too. The main applications are industrial equipment like telecommunication, measuring equipment, or circuits for micro signals in computers, their peripherals, AV devices etc.Metal oxide film relative resistorsThe resistive element is metal oxide film. The product is small (the smallest volume per rated power) size and has excellent heat resistant. Low T.C.R. is achievable by low cost compared to power type metal film resistors. Main application is power supply circuits.Wirewound relative resistorsThe resistive element is metal resistive wire. Excellent pulse resistance and heat resistance. Small T.C.R. and low current noise. Difficult to get high resistance and not suitable for high frequency circuits because of its wirewound construction.Those resistors are used as inruch current control resistors in power supply circuits. The products of low resistance are used for current sensing.
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Material construction and role
Basic of ResistorsWhat is Resistor?To understand a resistor, the important thing is to understand Ohm's Law, first of all.This is the basic knowledge.Ohm's Law means [the current what flows in to an electric conduction object is proportional to the voltage of both end of it] and defines the relationships between (E) voltage, (I) current, and (R) resistance as below.                R is proportionality coefficient and called resistance(electric resistance). Resistance volume code is R, unit code is Ω(ohm), and electronic symbol is expressed as below.[Electronic symbols of resistor]If the resistance is higher, the current will be difficult to flow, but easy to flow if the resistance is lower. In other words, resistor works to keep the current flowed to a circuit stable and to change it if necessary. Resistor also works to decrease the voltage or divide the voltage. Resistor is thus indispensable product for one of the fundemental components of electric circuit, as capacitors and inductors.Material construction and roleResistor is basically composed of following four elements.Base substrate: holds resistive body and terminalsAlumina type insulators are most used for base substrate of resistors.We have to select suitable material(thermal conductivity, thermal expansion of coefficient, mechanical strength) according to the purpose of resistor.Resistive body: part that determines basic features and performances of resistorElectric resistanceHere is the substance as shown in rightWhenSection area[cm2]:SLength[cm]:LSpecific resistance of the substance[Ω・cm]:ρElectric resistance R of this substance would be R=ρ・L / S [Ω]Terminal: part that connects resistive body and base substrate(circuit pattern) both electronically and mechanicallyVoltage or current is applied to terminal. Resistor should have suitable terminal construction and shape according to the mounting method.To improve the mounting density and to reduce the mounting cost, surface mount device(SMD) are predominated now.Coating: To protect resistive element and base substrate from air and mechanical stress.Construction example of resistorFlat Chip Resistor    Lead type Resistor(film type) 
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Selection of metal oxide varistors——KOA
Steps to select a varistorSteps to select a varistorThe basic steps for selecting a metal oxide varistor are shown in Figure 1. The following follows the basic steps to track the selected process through specific examples.Fig.1 Basic steps for selecting a varistorCase) Lightning surge absorption measures between power linesFig.2 Circuit examplevoltage VE=200(Vr.m.s.)±10%Surge voltage Vs=5(kV)Equivalent surge impedance ZS=100(Ω)Surge pulse width tT=50(μs)Load withstand voltage VP=800(V)Number of surges N=104times①Determining the varistor voltageFirst, select the appropriate varistor voltage based on the circuit voltage.1) According to the circuit voltage VE(V), the minimum value of the varistor voltage to be selected is determined by the equation 1.VE≦VV(min.)(1-α) …①VE:The peak of the circuit voltageVV(min.):Varistor minimum voltage valueα:Safety factor(α=0.1)In the example, the power supply voltage is 200Vr.m.s.±10%,Determine the varistor voltage with Equation 1VV(min.)≧(200√2 ×1.1)/(1-0.1)≧346(V)In the example, it is necessary to select a varistor with a lower limit of the standard range of the varistor voltage range recorded in the catalogue above 346V.In addition, there is a standard for varistor, that is, the upper limit of the voltage that can be continuously applied, that is, the maximum allowable circuit voltage.If a voltage exceeding this voltage is continuously applied, the varistor may be degraded, which also needs to be considered.2) According to the circuit voltage VE(V), the required maximum allowable circuit voltage is obtained by the equation ②.VE≦VA(1-α) …②VE:Circuit voltageVA:Maximum allowable circuit voltageα:Design margin(α=0.2)In the example, the supply voltage is 200Vr.m.s.±10%,Determine the varistor voltage with Equation ①VV(min.)≧(200×1.1)/(1-0.2)≧275(V) The nominal varistor voltage of the varistor needs to be selected according to the following two conditions: the standard range of the varistor voltage range is above 346V, and the maximum allowable circuit voltage is above 275V.For the product catalog, products with varistor voltages above NVDxxUCD390 should be selected.But this alone is not enough.It is also necessary to investigate whether the voltage suppression range of the varistor is appropriate when subjected to a surge voltage surge.If it is not appropriate, it may not be possible to obtain an appropriate voltage suppression effect at the critical moment of the surge voltage surge.②Calculate the inrush current through the varistorAssume that the circuit to be protected is Fig. 3, and the surge current Ip through the metal oxide varistor can be obtained by the equation ③.Fig. 3 Surge equivalent circuitIp=(Vs-Vc)/ Zs …③Ip :Inrush current Vs :Surge voltageVc :Varistor suppress voltageZs :Equivalent surge impedance Vc is less than Vs in most cases, so you can also ignore Vc for simple calculations.In the case, VS=5(kV)、ZS=100(Ω)、VP=800(V),According to type ③Ip=5000/100=50(A) ※Pulse Width tT=50(μs)It can be seen that the current value through the varistor is affected by the surge voltage 50(A)。③Determine the suppression voltage (limit voltage)The limiting voltage is selected according to the voltage-current characteristic curve of the product catalog, and the limiting voltage of the metal oxide varistor corresponding to the current IP obtained by the equation ③ should be VP or less with respect to the withstand voltage VP of the protection target (refer to Fig. 5).Fig.3  Relationship between voltage-current characteristic curve and IP and VPIn the example circuit, the nominal voltage of the varistor is above 390 (V),The maximum allowable circuit voltage is above 275 (Vr.m.s.), according to the voltage-current characteristic curve of the catalog,A metal oxide varistor having a limit voltage of 800 (V) or less corresponding to Ip=50 (A) is tentatively selected.The result obtained against this condition is...φ10 product:NVD10UCD430、NVD10UCD470φ14 product:NVD14UCD430、NVD14UCD470Need to choose from the above four products.④Determine the size of the disk diameterAccording to the surge current IP obtained by the transmission 3 and the surge pulse width tT(s) and the number of repetitions,Use a surge resistance and surge life characteristics (refer to individual standards) to select a metal oxide varistor within the allowable range.IP=50(A), tT=50(μs) calculated according to ③, repeated 104 timesSelect the surge tolerance and surge life characteristics of the product catalog.The result of comparing the product catalog is...NVD10UCDxxx:80(A)、NVD14UCDxxx:120(A)As can be seen from the results, these products are all larger than 50 (A), and the corresponding varieties of ③ can be used.However, the number of surges 104 times may contain uncertainties.If there is no problem with the placement, the design should leave enough margin.Select the φ14 product of the NVD14UCD type.The above is the general flow of selecting a varistor.I hope to provide a reference when you research varistor to cope with surges.
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Sensing current of DC/DC converter——KOA
Sensing current of DC/DC converterSensing current of DC/DC converterMicro processor requires larger current at lower voltage as the speed rises higher. A Desk Top Computer needs 40-60Amps, and even a notebook PC often demands more than 20Amps. Trends of resistor for current sensingResistance is decreased to measure an increased current. The resistance may be less than 2m.Some additional consideration is necessary for applications of such resistors.When the Resistance is very low,It becomes difficult to "sense the voltage precisely proportional to the current that flows through a resistor", which is a fundamental function of a resistor, when the switching frequency exceeds 100KHz(1)Minimize the inductance of resistor and PCB patternParasitic inductance on a resistor normally ranges around several nH and it is negligibly small for frequencies up to several 100KHz. But for an extremely low value resistor, minute inductance affects relatively large impedance to cause an error to the resistance.Example of the error by inductanceAn example is shown below. Parasitic inductance is assumed to be 1 nH in this figure.   Trimming disturbs the current flow    A resistor is trimmed to form a slit to adjust resistance.     This may cause a non-uniformity to the current flow, and may result in a heat spot. Local heating may aggravate the linearity of resistance vs. current.    (2)Resistivity should be uniform;     Not only a trimming line but voids at the junction with the resistor and the electrode might cause non-uniformity of current density.Tolerance of parasitic inductance might result in…An error in the measurement, while error compensation may be possible for a relative value. Influence from inductance can be contained in some degree by the use of filter. But scatter in parasitic inductance will also result in scatter of detected current values. In the figures below, simulations of the scatter of detected current values are shown.   (3)Electric potential across electrodes must be consistent;    The ratio of resistivity of electrode to that of resistive material is as small as several dozens for ultra low resistance. When the electrode is not thick enough, it cannot keep equi-potential regardless of the non-uniformity of current density inside the resistor. This means depending on where in the electrode voltage is extracted, resistance value varies.Selection guide for current sensing resistor:From the above discussion, current sensing resistor for large current should be:(1) Minimum parasitic inductance and minimum tolerance(2) Uniform structure of resistor and electrode(3)Minimum potential difference across electrodeUniform the current flow inside the resistorAbove conditions are achieved by completely getting rid of factors spoiling uniformity. Metal plate type resistor TLR, is developed under this concept. 特性Ultra low resistances (0.5mΩ~), suitable for large current sensingUltra low height with a thickness of 0.6mm, suitable for useof small equipment.Excellent high-frequency characteristicsAutomatic mounting machines are applicable.Suitable for reflow soldering. (Not suitable for flow soldering)Products meet EU-RoHS requirements.  AEC-Q200 qualified. Actual structure of TLRThe structure of TLR is shown. It has a flat resistive metal plate with bulk electrodes on it. Trimming is given not by slitting but by shaving the width of the plate as to keep uniformity. Thus the TLR is suitable to sense the current of DC/DC converters.Additional comments:The following considerations are still more necessary:(1)Fluctuation of detection in multi-phase DC/DC converter(2)PCB pattern design including current and voltage pads(3)Heat dissipation(4)Filter to minimize sensing errors
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Low Ohm Resistors——KOA
High precision | Low inductance | Large current type Current Sense Shunt series -Various kinds of lineup!The first step of power management of electronic devices is to measure the current. To measure correctly and efficiently, you need to select suitable current sense resistors for your application. Once you read this page, you can soon find your answer among KOA products offering from thick film chip construction to metal plate construction shunt.KOA's Currnet Sense Shunt / Low Ohm Resistors【Power Rating and Resistance Distribution of Current Sense Shunt / Low Ohm Resistors】※Click each product series to find the details-------------------------------------------------------------------------------------------------Features of Current Sense Shunt / Low Ohm ResistorsMotor control up to 244A and large current sensing of DC-DC converters and battery management.PSJ2/PSL2/PSG4/PSF4*Under Development.Power rating 12W max. achieved. Both 2- and 4- terminal constructions in our new product lineup. PSG4 and PSF4, 4-terminal construction type, enables high precision performance by T.C.R.+/- 50x10-6/K.---------------------------------------------------------------------------------------------------Motor control up to 600A and extremely large current sensing of DC-DC converters and battery management.HS*Under DevelopmentHigh current sensing possible even at low resistance 0.1mΩ, by voltage detecting terminals. Custom configuration available by various way of attachment.----------------------------------------------------------------------------------------------------Excellent high frequency characteristicsTLR The manufacturing process of resistors includes "trimming" process where the partial resistive body is cut to adjust the resistance. This trimming process would not cause any problem in the normal circuit, while it does cause various problem in the high speed circuit under large current.TLR series adjusts the resistance without trimming.[TLR - Heat dissipation distribution]1.The distribution of heat dissipation is uniformed without cutting in the resistor, leading to effective heat dissipation.[Detected Waveform]2.Measuring errorsis corrected, caused by the inductance of the resistor itself.---------------------------------------------------------------------------------------------------High precision sensing of large currentPS  Same construction of TLR, good high frequency characteristics. The stress of heat cycle is improved by the original shape pf PSB. PSE series achieves high power up to 5W in small size. KOA's lowest resistance 0.2mΩ and max. 250A current sensing available.---------------------------------------------------------------------------------------------------High reliable resistors under high temperatureResistive body molded by flame retardant resin, strong to temperature change and endurance. The terminals apply metal plate, which offers terminal strength and solderability. Wide operating temperature range from -55°C to +180°C, suitable for electronic devices under automotive environment.---------------------------------------------------------------------------------------------------Various size and power ratings. Selectable like general-purpose flat chipSR73SR73 1H is small type chip resistors, size 0.6mm x 0.3mm. Mountable on high density mounting devices like mobile phones, PDC and HDD.Applicable to various scenes like remain level detection of secondary battery and overcurrent protection circuit.---------------------------------------------------------------------------------------------------Low resistance under 100mΩ and realizes high precisionUR73 Resistance: 10mΩ~100mΩ & TCR:±100 x 10-6/K. Tolerance: ±1% is standard for this high precision resistors.Works excellent in the circuits like battery charge circuit, requiring low resistance(10mΩ~) and high power( up to 1W).----------------------------------------------------------------------------------------------------Wide terminal type and high powerWK73  Resistance: 10mΩ~100mΩ & TCR:±100 x 10-6/K. Tolerance: ±1% is standard for this high precision resistors.Works excellent in the circuits like battery charge circuit, requiring low resistance(10mΩ~) and high power( up to 1W).---------------------------------------------------------------------------------------------------Wide terminal, low TCR & high powerWU73  Resistance 13mΩ or more and TCR±75 x 10-6/K is achieved. Wide terminals achieves high power in small size. Excellent heat cycle, and suitable for devices requiring reliability such as automotive purposes
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Heat Cycle Characteristics—KOA
Heat Cycle CharacteristicsFor automotive applications where high heat cycle characteristics are required, solder cracks may be critical for flat chip resistors especially for large size. Solder crack is a phenomenon that crack is caused in solder when the temperature cycle, the gap of linear expansion coefficient between circuit substrate and chip resistor, is given to the solder junction area and the stress focuses on the area. It will lead to bad solder connection.When it requires large rated power, large size chip resistor is generally used while the large the product size is, the more frequently the solder cracks are caused. To achieve both high power and the countermeasure to solder cracks, plural resistors of the smaller size and the lower rated power are used but it will require the more number of components and the mounting surface area.In that case, wide electrode type WK73S, of high rated power and heat cycle or molded type TSL・SL・SLN is recommended.Wide terminal surface area offers excellent heat radiation and achieves rated power. Wide terminal type with reversal height and width against standard type, has short distance between electrodes. and higher heat cycle resistance. The rated power is higher because of the excellent heat radiation and wide electrode surface area.                             General-Purpose Type                                    Wide Terminal Type                 Molded type has terminal construction as below which enables to ease the stress of solder junction under heat cycle.
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High Voltage Type Resistors
High Voltage Type ResistorsOne of the role of resistors in a circuit is detecting high voltage by voltage dividing. Rated voltage and maximum working voltage are specified for each resistor, which should not be exceeded when it is used. Plural resistors have to be used in serial to the high voltage side of voltage dividing resistor, which requires more numbers of mounting components and wider mounting area. In this case, HV73or RCR of high max. working resistors can be used to reduce the numbers of mounting components. Especially for HV73, with excellent voltage constant compared to general-purpose chip resistors, can divide the comparative high voltage at high precision.Generally, resistor does not show a certain resistance against voltage. When voltage is high, the resistance will slightly decrease. Voltage coefficient is the indicator showing the decreasing rate of resistance at high voltage against the resistance at low voltage. Measure the resistance at 10% and at 100% of rated voltage or max voltage per element(max. working voltage), whichever is lower, and express on percentage(%/V) or parts per million(ppm/V).
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Anti-pulse/Anti-surge resistors
Anti-pulse/Anti-surge resistorsResistors that tolerate against pulse or surge are required to be used such as; precharge resistors in the circuit where large current is instantaneously applied or, resistors in the circuit where ESD is more likely to be applied. Pulse means the overload of large power and with long duration(large energy) whereas surge means overload like ESD, of high voltage and with short duration.Anti-pulse resistors are unlikely to be damaged even if large power is instantaneously applied. Among SMD type resistors, thick film chip resistors(metal glaze film type) are generally stronger against pulse than metal film chip resistors. Thick film chip resistors with special construction like SG73, or SG73P are strong against pulse or surge. Metal plate chip resistors for current sensing apply metal plate for resistive body. This achieves the strong resistance against pulse or surge. Leaded type resistors, on the other hand, wirewound type resistors that wounds metal resistive wire around the insulator such as CW, CW-H,RW, BGR, BWR, are stronger against pulse than film type metal film resistors or carbon film resistors that have metal resistive film formed on the top of insulator. Solid type ceramics resistors that applies ceramics resistive body, are extremely strong against pulse. Anti-surge resistor means a resistor strong against instantaneous high voltage like ESD. SG73S ensures the ESD limiting voltage.Pulse Resistance Level by resistor type(image)
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Anti Sulfuration Flat Chip Resistors
Anti Sulfuration Flat Chip ResistorsSulfuration is a phenomenon that occurs in the resistor that applies silver for *inner electrode. Typical product where sulfuration is concerned is thick film chip resistor. When a resistor is used under atmosphere including sulfur, sulfur inserts between protective film and outer electrode, which leads to reaction with silver of inner electrode. This reaction is called sulfuration. Silver sulfide produced through this reaction has no conductivity therefore resistor gets disconnected.Mechanism of Sulfuration             Sulfur is included as sulfur gas near hot springs or volcanos but also produced through firing of raw oil. Some rubber products apply sulfur to increase the strengths. When you use the above chip resistors under such atmosphere or near the product, the resistor should be prepared e.g. resin-molded. KOA's product lineup includes anti-sulfur type resistors that apply non sulfur type inner electrodes and slow-sulfur type flat chip resistors that sulfur is unlikely to insert.※ "Inner electrode" is the electrode that is not disclosed to outside of resistor, and is applied in order to connect resistive element and outer electrode(which is for soldering on the pattern) electrically.Anti-Sulfur Type ResistorsThick Film Chip Resistors RK73B-RT(general-purpose)/RK73H-RT(precision type)/RK73Z-RT(jumper), RK73G-RT(Ultra precision)Anti-Surge/Anti-Pulse Resistors SG73-RT, SG73S-RT(Anti-surge)/SG73P-RT(Anti-pulse)Wide Terminal Chip Resistors WK73-RTLow Resistance Resistors   SR73-RTHigh Voltage Resistors HV73-RTHigh Voltage Resistors(Automotive type)   HV73V-RTChip Network Resistors CN-RT(concave type) / CN-KRT(convex type)[Reference]Plant/Industrial equipmentCar eletronicsMachine toolsMobile telecom stationSewage treatment plant Waste disposal plantServer/NetworksPublic infrastructure
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Heat Resistance/Moisture Resistance Thin Film Resistors
Heat Resistance/Moisture Resistance Thin Film ResistorsThin film resistors have excellent characteristics such as high precision or low current noise whereas they have problem of being used under high temperature and high humidity. RN73H, with the improved heat resistance and moisture resistance than conventional thin film resistors RN73, can be used under severe environment like automotive purposes.Heat ResistanceApplying excellent heat resistance material to resistive body, all the type of RN73H except a certain size, achieve higher rated power than RN73. By extending the rated ambient temperature and max. operating temperature(the upper limit of operating temperature range)on the derating curve, the products can be used with higher applicable power at high temperature.Calculation example of applicable power at ambient temperature 100°CRN73 1J   Rated Power: 0.063W×0.455(45.5%)=0.029WRN73H 1J  Rated Power: 0.1W×0.786(78.6%)=0.079W(2.72 times compared to RN73)Moisture Resistance Electric corrosion may be occured in thin film resistors when they are used under high moisture enviroment. RN73H with special protective coating, improved the moisture resistance compared to conventional products and electric corrosion or disconnection are unlikely to be happened. This product shows the excellent characteristics compared to the conventional type in moisture resistance load life test of severe automotive test conditions. Comparison of moisture resistance load life testTest MethodLimitRN7340°C±2°C、90% to 95%RH、1000hrs(1.5hrs ON/0.5 hrs OFF)±0.5%+0.05ΩRN73H85°C±2°C、85%±5%RH, 1000hrs(1.5hrs ON/0.5 hrs OFF)±0.1%+0.05Ω
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Whitepaper EncoderBlue goes reflective——iC-PR,iC-PX
Whitepaper EncoderBlue goes reflectiveWith the continuously increasing adoption of auto-mated machinery in various applications, positioning devices are becoming an essential part of many systems. For precise motor control, encoders are becoming the most popular solution.An encoder can operate on different principles, such as: optical, magnetic, mechanical, etc., providing incremental or relative position data. An encoder may also provide multi-turn information when needed and all these possibilities result in a flexible product, offered in different sizes and suitable for all kinds of environments. Owing to this highly flexible nature of an encoder, together with the increasing use of automated machines, more and more applications are beginning to take advantage of position encoders.In order to better suit different applications and their specific requirements, new encoder technologies are constantly being developed and implemented. The reflective optical encoder with blue light is one example of such a new technology, and is being released by iC-Haus as the iC-PR and iC-PX Series integrated circuits.This article details the features and advantages of this new approach. Table of Contents1、 Fundamentals of optical encoders and new challenges     2、 Comparing transmissive and reflective optical encoders    3、 Reflective solutions                                    4、 IC-PR features and assembly tolerances                 5、 IC-PX features and assembly tolerances 6、 Advantages 7、 Applications 8、 Summary 9、 References Fundamentals of optical encoders and new challenges Ranging from industrial production lines to household appliances, automation is taking part in the design of most new products. In this context, linear and rotary encoders are the ultimate solution for accurate motor positioning, replacing aging components such as potentiometers, synchros, resolvers, etc.An encoder can operate on different principles, such as optical, magnetic, mechanical, and others. De-pending on the sensor type, an encoder provides incremental or relative position data. The first one outputs only information about changes in position, usually in the form of AB quadrature pulses. These are interpreted as forward or backward steps by a counter processor. Incremental encoders typically use a once-per-revolution index signal to reference the start or reset of the counting position. relative encoders, on the other hand, deliver the complete position value, which is available at any time (the relative position is known without requiring to pass through an index mark). relative encoders can also provide multi-turn information when needed, which gives the number of complete rotations of the encod-er.All these different operating modes result in a variety of products, offered in different sizes and suitable for all kinds of environments. With this highly flexible nature of the encoder, together with the increasing use of automated machines, more and more applica-tions are beginning to take advantage of the function-ality of position encoders for motion control.When comparing the different principles behind an encoder, optical encoders are regarded as the most precise ones. Each approach has its own benefits, with optical encoders usually providing the highest resolution and accuracy. However, optical encoders also come with their own disadvantages. Due to its optical nature, the sensor components are sensitive to dust, oil, and other obstacles that may interfere with the optical path. This is usually solved by a tightly sealed enclosure for the encoder. Another difficulty faced by high accuracy optical encoders is the influence of position errors, meaning that assem-bly tolerances are generally very small. This leads to a higher complexity in the manufacturing process of the encoder, requiring high accuracy assembly techniques to achieve proper signals. This problem alone impedes many companies from manufacturing encoders, since their manufacturing process cannot achieve the required level of precision.Another difficulty faced by some applications regard-ing optical encoders is the space required by the encoder. An optical encoder must have a protective case, and the internal structure required by traditional (transmissive) optical encoders result in a considera-ble height (Z dimension). This is due to the fact that the light source (LED), code disc and optical sensor must be optically aligned with a suitable distance between them. This requires an encoder height that prevents it from being adopted in some compact applications, such as miniaturized robotics.Even consumer products are entering the realm of fine positioning control with the introduction of household vacuuming robots, flying drones, and house automation (auto-adjustment of curtains, ventilation, etc.). The manufacturing of these products is executed on a large scale, and assembly variations must be accepted in order to have a high production efficiency. Additionally, the compact sizes of some of these products also prevent the adoption of large-dimension encoders, which are usually acceptable for industrial machines.The first solution to these requirements would be the use of magnetic encoders. Simple on-axis magnetic encoders can be easily manufactured and require very little space, thus representing a logical choice. However, as the resolution and accuracy require-ments of these applications also evolve, the magnetic encoders are faced with a technical limitation. Currently, on-axis magnetic encoders cannot reach very high resolutions and neither do they provide the highest accuracy unless more advanced techniques are used (for example: using external interpolators to increase the resolution of the system), which unfortu-nately results in higher costs. Additionally, magnetic encoders require more robust shielding against magnetic interference, which in some working environments can be very challenging.These new demands driven by the market have inspired the industry to search for ways to adapt the characteristics of the optical encoder, making it implementable under these new conditions.Comparing transmissive and reflective optical encodersTraditional optical encoders rely on transmissive optics, which is a mature and well-known technology for encoders. However, it also has its own inherent drawbacks, limiting its application in certain scenari-os. An alternative technology for encoders is based on reflective optics, which tries to improve on the features where transmissive encoders tend to fall short. Although transmissive and reflective encoders use the same basic principle – an optical sensor that receives light modulated by the movement of a coded disc – their physical structures differ considerably. The figure below represents the basic structure of a traditional transmissive encoder:Figure 1: Basic structure of transmissive optical encodersAs illustrated in Figure 1, the transmissive solution works fundamentally by using the code disc to create obstructions to the light path at some places while letting the light through at other places. The main requirement of the code disc is a precise division into transparent and non-transparent areas. This is usually achieved by a lithographic process, where a coating material (such as chrome) is deposited on top of a transparent substrate (such as glass). The quality of the disc is defined by the accuracy of the litho-graphic process, as well as the contrast between transparent and non-transparent areas.The advantage in this technique is that the lithograph-ic process is mature and can achieve very high accuracy, allowing a very fine code marking on the disc. This results in better signal quality for high resolution encoders.On the other hand, this structure also brings disad-vantages: in order to achieve good results, the illumination has to be as homogeneous as possible. This requires a parallel light beam that is achieved only by adding collimation lenses to the system. This optical structure considerably increases the axial length of the encoder, which is undesirable for many applications.Another disadvantage is that the accuracy with which the sensor must be positioned relative to the code disc is directly related to the density of the marking on the disc. If very precise lithography is used, the position of the sensor relative to the code disc must also be very precise, otherwise the quality of the signals will suffer considerably. This includes the XY displacement of the sensor, as well as the air gap between the sensor and the code disc (Z distance). If the marking on the code disc is very narrow, the light diffraction after going through the disc will have a bigger impact on the signal, therefore a very tight air gap between sensor and disc is required in order to receive good signals. For high-end encoders, assem-bly accuracy requirements are under 0.1 mm, which unfortunately is unfeasible for many manufacturers. Even for manufacturers that achieve such accuracy requirements for the end product, the assembly still requires a careful positioning calibration, usually conducted individually for each encoder using optical or electrical inspection and followed by a fine correc-tion of the generated signals. This process is very time consuming, limiting the efficiency of the manu-facturing process.The problems mentioned above can be tackled by using reflective optical encoders. The figure below depicts the structure of this kind of solution:Figure 2: Basic structure of reflective optical encodersThe most evident difference seen in Figure 2 com-pared to the transmissive solution, is the absence of the light source with collimation lenses opposite the sensor. A reflective encoder works by emitting light from the same side as the sensor (relative to the code disc), and selectively reflecting portions of the light to the sensor. In this case, the fundamental characteris-tic of the disc is the division between reflective and non-reflective areas (in contrast to the transpar-ent/non-transparent nature of the transmissive discs). As with the transmissive discs, the quality of the signals depends on the disc marking process (lithog-raphy) and the contrast between the divided areas (in this case, reflective/non-reflective).Reduced physical dimensions is a noticeably clear advantage of this solution. Without collimation optics, and with the LED light source on the same side as the sensor, the total volume of the encoder can be reduced substantially. This factor alone already enables the encoder to fit a wider range of applica-tions, compared to the transmissive solution. Com-pact optical encoders are possible, sharing many of the advantages of traditional optical encoders.The reflective encoder solution can have different variations. A typical example is the addition of plastic lenses on top of the sensor and LED to shape the light beam to have the desired properties. However, an even better solution is achieved using a lens-free design. Eliminating the external lenses completely can be accomplished and results in more flexibility and robustness: lenses need to be specifically designed for different applications, they limit consid-erably the operating distance range between the LED/Sensor and the disc, and at the same time add restrictions to the operating conditions, such as the allowed temperature range. Even without additional lenses, very high resolutions can be achieved by carefully controlling the light source spot size. With standard LED illumination, it is already possible to achieve medium-high resolutions with this approach.In this case, we see the most advantageous scenario: as long as the resolution is kept in a reasonable range, we have an optical encoder with very small dimensions, no external optics requirement, good resolution and accuracy (which can be easily en-hanced further with interpolation techniques), and very low assembly requirements.We can compare main characteristics of transmissive and reflective encoders:Transmissive Optical Encoder:Mature techniqueHigh resolution and high accuracySignificant height (Z dimension)Difficult assembly: small tolerances, mechanical stability during operationSmall code disc to sensor air gapGood resolution and accuracy:Easy assemblyLarge mechanical tolerancesFlat design: decreased heightLarge code disc to sensor air gapReflective solutionsThe reflective optical encoder principle has been known for some time. However, difficulties in achiev-ing good results in a convenient and easy to use integrated chip have limited its implementation to a few product lines from a small number of manufactur-ers.The recent introduction of the EncoderBlue® products (optical encoders with blue LED as light source) has proven useful also for the reflective encoder segment.The EncoderBlue® technology provides many ad-vantages, such as:higher efficiency (same optical power with less operating current),higher signal sharpness and contrast,less output signal jitter.The EncoderBlue® technology is already in use with transmissive optical encoders (such as the iC-PT H-Series and iC-PNH Series), but these properties can also considerably improve the signals in reflective encoders. Therefore, iC-Haus combined the ad-vantages of EncoderBlue® technology and the reflective encoder approach, releasing the all-new incremental optical encoder iC-PR Series and iC-PX Series.IC-PR features and assembly tolerancesThe first product carrying the reflective EncoderBlue® technique is the iC-PR Series. This is a lensless reflective optical design for an incremental encoder.ABZ digital quadrature outputs with up to 16-fold interpolation is possible. This interpolation is realized on-chip through pin configuration. There is the optional functionality of providing the analog signals at the output. The analog sine/cosine signals can be connected to an external interpolator for enhanced interpolation.As expected from an EncoderBlue® solution, the iC-PR encoder also integrates a blue LED to be used as the illumination source. This blue LED comes with all the previously mentioned advantages, and is driven by a closed-loop control circuit, which automatically adapts the LED current according to the amplitude of the signals generated by the sensor. This ensures a stable operation of the encoder, compensating variations such as LED efficiency deviations due to temperature or aging effects, or even mechanical variations such as the air gap between the chip and the code disc.The iC-PR Series is composed of different variants, each with HD Phased Array photosensors optimized for a specific code disc diameter and resolution. All the selectable functions are configured by pin, thus do not require time-consuming programming proce-dures.The main features of the iC-PR Series are listed below:ABZ quadrature output with indexNo optical lenseOptimized for reflective code discs of Ø 4, Ø 14, Ø 26 and Ø 43 mmMonolithic design: integrated HD Phased Array, signal conditioning, S/D conversion and LED power controlIntegrated blue LED with auto power control: EncoderBlue®The main features of the iC-PX Series are listed below:AB quadrature outputNo optical lensOptimized for reflective code discs of Ø 26 and Ø32 mmMonolithic design: integrated HD Phased Array,signal conditioning,S/D conversion and LED power controlIntegrated blue LED with auto power control:EncoderBlue®Digital output (pin selectable 1x to 16x interpolation)Operating temperature: – 40 °C to + 105 °CoptoDFN package 3 x 3 x 0.9 mmLow power consumption: typ. 13 mA (incl. LED)Due to the absence of an index mark, the mounting ofthe sensor relative to the code disc is even moreflexible. Figure 4 shows the typical assembly variationtolerances for the iC-PX Series.AdvantagesStandard package: This all-integrated solution isassembled in an optoQFN for the iC-PR (QFN dimensions with a glass window for the opto sensor) and optoDFN for the iC-PX, which eases the PCB design considerably. The footprint as well as the chip height is the same as other QFN/DFN standard ICs. This eliminates the hassle of creating design-specific PCB footprints, required by other reflective products in the market.                                                                                                                                Figure 5: Standard QFN/DFN footprint and dimensions for iC-PR and iC-PXHigh-temp and overall height: These reflective encoder ICs do not hinge on any lens or secondary optics and therefore reduces the overall height of the encoder housing. A plastic lens would not only increases the height of the system, but also limits the maximum operating temperature, usually to + 85 °C. With such lensless reflective technology, the maxi-mum operating temperature is + 105 °C, as often required by the industry.Wider air gap: Another limitation of a reflective solution with a lens is the air gap range. Due to the focal length of the lens, the gap tolerable range is narrow, usually ± 0.25 mm. This reflective technique unites a lensless design with an automatic LED power control, which together increase the permissi-ble air gap range to 1 to 3  mm, always with stable outputs.Higher quality signals: These reflective solutions also integrate a blue LED and HD Phased Array photodi-odes, optimized for different disc sizes. The blue LED together with the blue-enhanced HD Phased Array photodiodes generate sharper signals with higher contrast. This results in reduced output jitter, even after interpolation. The photodiodes are optimized for different code disc dimensions covering a wide range of diameters, even an ultra-compact 4 mm diameter disc. This optimization is especially important when using the analog outputs for external interpolation, as the quality of sine/cosine signals remains outstand-ing, allowing high-accuracy and high-resolution interpolation                                            Figure 6: Basic optical design and ray tracing model of a reflective encoder sensorEasy to use: The iC-PR and iC-PX Series are com-pletely pin configurable, avoiding the complexity of programming and calibration, and thus reducing the encoder manufacturing time. Together with the relaxed assembly tolerances, the overall efficiency of the encoder production line can be increased consid-erably.ApplicationsThe reflective encoders can be used in different applications, sometimes as a replacement for other types of encoders and in some cases in new applica-tions not yet served by current encoder technology.Most motion control devices with incremental posi-tioning detection can benefit of the iC-PR or iC-PX Series, but the main focus of the reflective encoders is on compact encoder applications, such as:Miniature motors and actuatorsIndustrial automation robotsConsumer robotsIncremental encodersSingle or multi-axis stagesSummaryThe level of automation is rapidly increasing in all areas, ranging from industry machinery to household appliances. This is creating new requirements for encoders, an essential device for motion control. In this context, reflective optical encoders represent a new technology that unites high performance and compact size.In particular, the reflective optical encoders by iC-Haus with EncoderBlue® technology offer not only small dimensions, but also robustness and superior assembly tolerances, all while providing excellent output signals.The iC-PR and iC-PX Series are easy to use and suitable for all kinds of incremental encoders without bringing complexity to the manufacturing process. This allows a broader range of products for precise motion control.References[1] Wikipedia: Rotary Encoder, https://en.wikipedia.org/wiki/Rotary_encoder[2] relative Encoder Design: Magnetic or Optical?, Whitepaper iC-Haus, http://www.ichaus.de/wp6_magnetic_vs_optical[3] iC-PR Series – Reflective Opto Encoders, Datasheet iC-Haus GmbH www.ichaus.de/PR_Series_datasheet_en[4] Basics of Rotary Encoders: Overview and New Technologies, http://machinedesign.com/sensors/basics-rotary-encoders-overview-and-new-technologies-0[5] Basler S. (2016) Encoder und Motor-Feedback-Systeme, Springer ViewegAbout iC-HausiC-Haus GmbH is a leading, independent German manufacturer of standard iCs (ASSP) and customized ASiC semiconductor solutions with worldwide repre-sentation. For more than 30 years the company has been active in the design, production, and sales of application-specific iCs for industrial, automotive, and medical applications.The iC-Haus cell libraries in CMOS, bipolar, and BCD technologies are specifically suited to realize the design of sensor, laser/opto, and actuator ASiCs, amongst others. The iCs are assembled in standard plastic packages or using the iC-Haus chip-on-board technology to manufacture complete microsystems, multichip modules, and optoBGA/QFN in conjunction with sensors.Further information is available at www.ichaus.com
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高度集成化电路趋向---无源器件内置 XR73
省空间计划——无源器件内置简介:跟着科技的日趋开展,无论是工业产品,仍是各类消费类电子产品,对体积和空间的要求愈来愈严厉。比方,世界第一台计算机的体积如同一座小楼,而现在的计算机却能够做到如手掌的巨细,人类文明的进步,培养了产业和手艺的高速开展。一样在各类高速开展的科技信息行业中,集成电路开展有着急剧的变革,从lead引线元件到大规模的SMD,从简单的单层PCB发展到多层PCB通孔毗连,从高功率大体积到低功耗小尺寸的变迁。而近年来嵌入式电阻和电容的手艺又走在了科技的前端,也将代表着下一个时期和将来的趋向。在此之前,人们曾经发清楚明了多层PCB板手艺,此中焦点的部门就是各人熟知的微过孔手艺,其差别层的PCB布线经由过程激光通孔,附铜毗连。在使用中,在一定程度上减小了PCB电路布线的面积,只留下元器件所需的空间和尺寸。而无源器件的内置手艺,将更有可能改动电路设计的相貌。微过孔电路实现了更高的密度、更轻的重量和更好的机能,但电路板自己仍是很多导线的毗连体。而接纳无源器件内置手艺后,电路板将变得完整不同于以往。其被动器件(如:电阻、电容)将会被集成在PCB内部,而内部不会留下任何无源器件,如许PCB的空间和尺寸会被紧缩至最小!无源器件内置是一个相对较新的观点,今朝诸多公司都在打仗和研讨这个新的手艺,因此在国内市场上还未获得遍及使用,形成这个状况的制约身分次要有两点:1、海内今朝未有整套完好的系统去考证该方案的可靠性以及稳定性。2、PCB厂家的消费加工手艺,需求高精细的仪器和生产技术才气共同到嵌入式PCB的设想和开辟。但就算是存在着诸多难点,为什么要内置它们呢?究其根本原因不过就是电路板外表空间慌张,客户产物在往小型化,高度集成化标的目的开展。在典范的消费装配中,占生产成本很小的元件部门可能会占有PCB大部分的空间,而且这个状况愈来愈严重。由于我们设想的产物需求撑持愈来愈多的功用,招致其项目设想中要撑持更多的功用、更高的时钟速率和更低的电压,这就要求有更多的功率和更高的电流。同时还需求对电源散布体系停止很大的改良。这统统都需求有更多的无源器件(如:电阻、电容),而无源器件的增长,必将会占有相称大一部分PCB空间。无源器件内置的优势:      1、 节省了贵重的电路板外表空间,缩小了电路板尺寸并削减了其重量和厚度。      2、 嵌入的方法因为消弭了焊接点,因而削减了引入的电感量,从而低落了电源体系的阻抗,可靠性获得很大提高(焊接点是电路板上最简单引入毛病的部门)。      3、 无源器件的嵌入将减短导线的长度,而且许可更松散的器件规划,从而提高电气机能。嵌入式电阻:目前市场情况中某些建造嵌入式电阻PCB的方法是接纳双金属层构造——铜层与一个薄的镍合金层组成了电阻器元素,然后经由过程对铜和镍的蚀刻,构成具有铜端子的各类镍电阻,而且间接与布线相连接,然后这些电阻器被层压至电路板的内层中。该手艺曾经被应用于通讯设备中,如:卫星、基站。而在医疗电子设备、航空电子设备和电脑装备中也得到了使用。嵌入式电阻不只能够节省空间、削减重量和尺寸。同时也能够提拔电子机能。日本专业电阻生产商KOA在电阻行业有长达60年以上的消费和研发经历,对应着新型PCB产业的手艺,固然也不会落伍,其XR73系列电阻,能够完整内嵌于PCB设想的电路中,并具有很好的公役和其他尺度的电阻特性,XR73系列电阻为一个零丁的抵御体,较上述部门的嵌入式电阻方法,在阻值偏差,温漂,以及一些噪声和各批次间的一致性身上有着共同的优势,由于XR73是个完好的个别,是接纳尺度的电阻生产技术来完成的,其温度掌握和功率掌握,以及阻值掌握部门都存在着很大的灵活性,而且该系列嵌入式电阻的使用,能够在广大的双面铜电极上间接停止微过孔毗连PCB的布线,以是帮助PCB的印制,少了许多工序,能够间接层压到PCB中。以下为KOA XR73的根本框图以及相干的尺寸:                                能够从图中看出,其内部架构,保护膜,根本散热部门,电极部门都是非常的完好。而且此中有两个部门有着和凸起的表示:1.     面积很广的双面电极。2.     十分低的厚度值,可达0.14mm.在嵌入式无源器件PCB中接纳该系列的电阻使用有着以下的优势:1、高集成度。该系列使用经由过程三维可视化的安装方法较一般的SMD贴片有高精准性和稳定性的优势。2、高散热性。各人熟知,假如嵌入式电阻的温升太高,将会形成整块PCB的热量过大,后续不得不借助核心器件散热,而XR73系列在温升掌握方面十分优良,接纳导热率高的树脂充任电阻外层的保护膜。          3、高可靠性:将电阻层压至PCB中,而PCB外层相当于电阻的物理情况保护膜,以是对电路的稳定性有很大的提拔。     4、高优良抗蜿蜒性及抗震性。内嵌式电阻较大的短处的一部分在于电阻一旦潜入在PCB内部,它的电极部门被牢固,当热胀冷缩,和内部高强度机器应力蜿蜒电路板时,会对内嵌的电阻有个十分严重的磨练, XR73系列接纳了相干的手艺可以接受一定程度的蜿蜒和热胀冷缩磨练,而且KOA内部的测试针对该项目标要求也非常严厉,接纳大批量的蜿蜒0mm~1mm,0mm~5mm规格,测试后电阻的偏差必需掌握在公役范围内。5、十分优良毗连性。 在上文中也提到过微过孔手艺,内嵌式电阻再加上微过孔手艺,不只能够将电阻内嵌在PCB中,而且PCB还能够多层化,而如许就会愈加节流空间。XR73系列最大亮点在于,它是双面电极,而且电极部门是由Cu制成,具有很强的抗震性,而这一特性有着十分明显的使用---那就是XR73系列能够在电阻的电极上施行微过孔手艺的同时与多层PCB的毗连。   总结:    其无源器件的嵌入式PCB,将会是一个趋向,目前国内诸多的电子产品和一些终端设备的研发和制造商,都十分存眷这个范畴,将其作为一个手艺的储备,不竭的去探究。嵌入式PCB能够较一般PCB的生产成本会提高,可是其对设想的改良(更小的尺寸,更少的层数,更轻的重量),安装用度的节流(从双面安装变成单面安装),以及带来的机能提拔都该当被考虑到。跟着工艺的进步、产量的增长以及合作方的兼并,本钱必然会降落,使用也将会更普遍。
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EncoderBlue goes reflective—— iC-PR Series
新产品:iC-PR 系列 蓝光反射式编码器       iC-PR系列是一个先辈的光学,反射式,无透镜的编码器,具有集成的高密度相控阵光电传感器和一个蓝色LED。芯片供给高旌旗灯号质量与宽松的装配公役。差分数字ABZ输出有或没有插值,或输出模仿SIN/COS带索引可选择利用。典范应用于机电掌握的增量编码器。蓝色加强的光电传感器顺应嵌入的短波长蓝色发光二极管,并提供低颤动输出因为提高了旌旗灯号对比度。共同的蓝色发光二极管和传感器装配手艺致使具有低光学串扰。 特性无透镜反射式光电编码器芯片,松散,高分辨率,增量适宜的反射式编码盘Ø 4, Ø 14, Ø 26 和Ø 43 mm单片高密度相控阵列具有优良的旌旗灯号婚配机能集成蓝色LED具有功率掌握功用,EncoderBlue ®低噪声旌旗灯号放大器具有高EMI容忍引脚可选操纵模式:数字A / B / Z(x1,x2,x4、x8、x16的插值);模仿COS / SIN带用模仿或数字Z旌旗灯号索引选通:不选通( 1 T ) ,B选通(0.T),AB选通(0.25 T )引脚可选择最小边沿间隔:80 ns, 1 μs, 10 μs互补正交输出 PA, NA, PB 和 NB互补索引输出 PZ 和 NZ模仿旌旗灯号输出便于装配瞄准和经由过程内部插补器提高分辨率工作温度范畴:–40℃ ~105℃松散无透镜optoQFN封装(4 mm x 4 mm x 0.9 mm)可供给评价套件 使用增量编码器微型马达和施行器X-Y和线性使用工场自动化机器人消耗机器人
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17位绝对值磁编码器-MU1C离轴机电反应模块
MU1C离轴机电反应模块使用扭转编码器机电反应运动掌握 特性磁性离轴绝对位置编码器模块17位位置数据输出经由过程BiSS/SSI快速串行接口正交ABZ旌旗灯号输出经由过程RS-422线驱动器iC-HF或Sin/Cos输出经由过程线驱动器iC-MSA可编程分辨率1到32,768 (FlexCount)位置预置功用扭转速度达12,000 RPM5V电源供电具有反极性庇护工作温度范畴 -40 °C 到80 °C评价板套件包罗磁码盘MU2S 30-32N和线缆设置用户图形界面软件带主动校准功用 方框图
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iC-MU150离轴磁性游标编码器 - 极宽1.50 mm
iC-MU150特性集成霍尔传感器双轨道扫描霍尔传感器优化为1.50mm极宽(主码道)旌旗灯号调理偏移、幅度和相位12位分辨率的正弦/数字及时转换(14位过滤)2轨道游标绝对值计较高达18位16、32或64极对丈量间隔利用两个iC-MU150增长丈量间隔与内部多圈体系同步从内部EEPROM利用多主机 I2C接口设置兼容的微控制器串行接口(SPI,BiSS,SSI)增量正交旌旗灯号带索引(ABZ)FlexCount®:灵敏的分辨率设置从1到65536CPR 使用扭转绝对值编码器线性绝对标准单圈和多圈编码器机电反应编码器无刷直流电机换向空心轴编码器封装:方框图方框图:
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High-Precision Sine/Cosine Interpolation
高精度-正弦/余弦插值细分法现有的驱动控制器需求装备有高分辨率的磁电或光电定位传感器以实现速度掌握大概定位的功用。所利用的传感器需求专门装备集成电路,用于传感器旌旗灯号的调理以及正弦/余弦旌旗灯号向数字信号的转换。此份白皮书形貌了"细分器"在正弦/余弦旌旗灯号向数字信号转换(S/D转换)的办法以及相干手艺应战,其一样也会商了与传感器相干的测量误差以及对其抵偿步伐,并展现了最新的芯片解决方案以及如何对其停止挑选。目次:1.  正弦/余弦旌旗灯号向数字信号的转换办法..........21.1 快闪型(Flash) 转换器.......................21.2 矢量跟随转换器.............................31.3 采样连结型的SAR转换器......................41.4 连续采样A/D转换器..........................41.5 插值细分组件比照...........................52.  带有示例的测量误差.........................62.1  旌旗灯号调理的观点............................93.   总结......................................134.   参考文献..................................13 白皮书正弦/余弦旌旗灯号向数字信号的转换办法高精度的磁力大概光电传感器[1]能够将角度信息大概长度信息以90度角的情势停止编码并转换为正弦大概余弦旌旗灯号。此中利用细分器停止非线性的A/D转换,其用于将正弦/余弦旌旗灯号转换为转角阶跃(拜见图1),其能够用增量旌旗灯号也被称为正交旌旗灯号停止展现,也能够用绝对数值字段停止展现该字段所表达的正弦旌旗灯号的相位角。图1:经由过程”细分器“的角度转换非线性转换函数凡是利用反正切函数,如许相位角PHI能够间接从正弦和余弦电压中得到。多种A/D转换观点可应用于:快闪型转换器,比方iC-NV,利用了多个自力的比力器;矢量跟随转换器,比方iC-NQC以及iC-MQF,其仅装备了几个比力器,用于对控制器在向上大概向下的方向上停止初度旌旗灯号收罗,然后对所输入的角度停止跟随;SAR转换器,比方在iC-MR中说起的,在基本原理上与矢量跟随转换器类似,但会连结输入旌旗灯号直至得到响应的计数值;利用线性A/D转换器(比方:在iC-TW8中利用的)也能够停止角度计较,此中该A/D转换器能够别离将正弦和余弦旌旗灯号停止数字化处置.  完整集成了磁电和光电感到的单芯片编码器,比方iC-MU大概iC-LNB,利用矢量跟随转换器来及时供给位置数据[1,2]。1.1 快闪型(Flash) 转换器图2展现了一种带有多个自力比力器的快闪型转换器,在差别正切函数阈值时停止切换。最少一个比力器用于定义一名角解析度,也意味着对其装备的硬件要求十分高,以是需求利用很大的芯片面积–除非抛却精细电路。因而,这类情势适用于较低分辨率同时精度要求也其实不是出格高的计划。 图2:快闪型转换器快闪型转换器有许多长处:其比力器能够并行事情而且险些同时完成旌旗灯号转换。因为在成立不变的历程中会构成转换毛刺,因而利用了边缘间隔掌握的专利技术用于成立平衡。当持续边缘到来时,假如其距离过近会推延,则会发生一个可计数的输出旌旗灯号-电路起到滤波器的感化,并且未受滋扰的输入旌旗灯号在经由过程时其实不会发生提早,也就是说该滤波器的感化不会发生任何提早结果。快闪型转换不需要停止采样。因而,因为发生的正交旌旗灯号不会和任何时钟旌旗灯号同步,所以此旌旗灯号带有“模仿的”颤动特性–这类特性关于速度掌握十分合用。典范应用于光电或磁性机电编码器。1.2 矢量跟随转换器矢量跟随转换手艺次要应用于停止更高的剖析(拜见图3)。其装备有一个低级比力器,该比力器用于掌握计数器向上或向下计数。数字计数器将数值输入一个D/A转换器并天生模仿正切旌旗灯号。该正切旌旗灯号同余弦旌旗灯号混淆,并天生一个正弦旌旗灯号-然后将正弦旌旗灯号停止比照。图3:矢量跟随转换 白皮书当体系不变后,计数器包罗相位角而且逐渐长大概说逐比特位的记载每个输入旌旗灯号的变革。这个历程中不会发生阶跃。矢量跟随转换器的优势是该体系的功用与时钟无关,体系仅在输入发作变革时才会被触发,如许能够收缩体系的延迟时间。因为该体系仅需求一个比力器,因而其设想能够做到愈加精细。潜伏的电路中的偏移偏差会以一样的方法对所有切换点发生不异影响–可同迟滞征象比力–因而该体系在精度方面也具有必然优势。跟随转换器输出递增旌旗灯号时会发生响应的模仿颤动。当到达可调的最高跟随速度的限定时,时钟同步影响才会显现出来,比方在输出旌旗灯号时发作毛病。基于及时以及高解析度的特性,该范例转换器被作为线性位置丈量体系的首选。1.3 采样连结型的SAR转换器 关于不需要输出递增旌旗灯号的绝对丈量体系来讲,图4所展现的采样转换器是一种适宜的挑选。SAR(逐次迫近) 转换器的事情道理同矢量跟随转换器道理类似,差别的是逐次迫近寄存器能够更快获得附近的相位角,由于其步长能够更大且事情时不需要逐比特位停止跟随。图4:采样连结型的SAR当遭到内部数据恳求触发时,体系经由过程采样连结电路对输入旌旗灯号停止解冻。在该体系中,模仿旌旗灯号的不变工夫次要决议了转换的速率和精度。此范例的转换器凡是应用于机电控制系统以及逆变器等关于角度旌旗灯号有较高解析度要求的体系中,其能够对模仿编码旌旗灯号大概位置编码旌旗灯号停止处置。1. 连续采样A/D转换器典范的办法:iC-TW8利用连续运转线性A/D转换器(图5)然后对相位角停止计较。该体系的优势在于数字信号处置:旌旗灯号偏差既能够经由过程一次性按动按钮停止初始化校准后消弭,也能够连续的经由过程主动传感器漂移抵偿停止校订。图5:采样A/D转换器旌旗灯号滤波的利用使得解析度超越实践可用A/D转换器解析度成为能够。分解发生的增量输出旌旗灯号的完善占空比为50%而且几乎没有颤动。可是,在体系掌握时也需求思索对因为旌旗灯号处置所招致的几微秒的恒定延迟时间。该转换器次要应用于高解析度的线性测长仪以及受益于供给主动旌旗灯号校订的扭转式编码器体系。插值细分组件比照 不必赘言,利用什么品种的转换器由其使用范畴决议:挑选跟随转换器iC-NQC以及iC-MQF的缘故原由是由于其具有及时的特性,最小延迟时间不超过250 ns,这凡是经由过程模仿途径运转工夫决议。关于采样转换器iC-MR和iC-TW8来讲,丈量数值时的不变工夫(拜见表1)至关重要,其决议了能够实现的采样率。iC-MR能够在2微秒内利用13bit对角度位置停止剖析,而持续运转转换器iC-TW8需求24微秒并采样6个样本用于更新位置数据。另一方面,假如速度是恒定的,iC-TW8能够经由过程可调的数字滤波器将现有的提早期低落到4微秒内。和扭转变压器的处置一样一般,但是输出位置信息能在相称短的时间内追逐输入角度。表1:转换特性白皮书 除剖析度外,一样需求思索精度,转换器的精度不只同A/D转换器的处理器质量相干,同时也与旌旗灯号调理的范畴值相干。每一个针对旌旗灯号途径停止改正的D/A转换器都需求预留芯片面积,响应的也会招致本钱的增长-因而关于电路设计者来讲需求停止优化设想。表2中器件比力显现iC-MQF转换器的解析度与iC-NQC的解析度比拟要更低。不外,因为具有更精细的分开旌旗灯号调理,因而其精度更高。安全导向的编码器体系需求一些附加功用:iC-MR器件具有特别的诊断功用,比方:旌旗灯号和温度监控,内存查抄以及毛病模仿。关于控制器通信,一个并行接口以及多个串行接口都可用。经由过程设置BiSS C上的位置数据输出,能够增长安全计数数据及扩大至16位CRC校验。表2:操纵特性2.      带有示例的测量误差如有必要,需求对图6中示例唆使的在磁环扫描历程中利用磁阻传感器招致的测量误差停止思索。 图6:带有偏差源的使用实例 白皮书 潜伏的偏差源能够是:不精确的磁化丈量目的磁阻传感器偏移大概幅度招致的旌旗灯号偏差不精确的传感器位置对齐招致的正弦/余弦相位偏差毛病调理或调理不敷招致的旌旗灯号偏差不精确转换招致的测量误差假如没有响应的抵消步伐,会发生毛病的插值细分成果,因而增量输出旌旗灯号较着颤动较强。一方面机器角度变动招致的输出颤动是能够承受的,可是另一方面因为丈量系统误差招致的颤动是无法承受的-使人遗憾的是,无法对这二者停止辨别大概婚配。因而,关于潜伏偏差源的准确熟悉是非常重要的。角度计较公式表白了我们需求对哪些旌旗灯号偏差停止思索:公式:经由过程反正切函数的角度计较 与其相干的偏差源有:偏移电压,与幻想相位差之间的偏向,正弦与余弦幅度之间的偏向,能够的谐波波形扭曲。因而,我们需求知道这些旌旗灯号偏差能否需求停止“调理”大概该偏差能够被无视。 三个实例预算对调理精度的要求:磁性,同轴,1CPR:0.1度(12位)精度:       要求旌旗灯号偏差磁性,离轴(32对磁极),64CPR:0.1度(12位)精度:       要求旌旗灯号偏差光电,离轴,2048CPR:20秒(16位)精度:       要求旌旗灯号偏差 白皮书 实例1:假如希冀机器角度精度为0.1o(12位/每转)同轴霍尔传感器体系,每转供给一个正弦周期旌旗灯号,那么能够揣度出每一个旌旗灯号偏差必需低于0.2%。虽然野生手动调理十分费时且关于现有的丈量装备也是一个很大的应战,可是仍旧能够实现精度调理。调理东西拜见:http://www.ichaus.de/tools合适的器件:iC-NQC,iC-TW8,iC-MR 实例2:利用磁阻传感器采样磁环时,可低落对插值细分深度和技术上旌旗灯号精度的要求。尽管如此,愈加准确的调理仍旧需求依赖于丈量目的磁化的准确水平。输入频次跟着极数的增长而增长-因为插值细分倍数的削减,因而其关于矢量跟随转换器来讲也其实不是成绩。合适的器件:iC-TW2,iC-MQ,iC-NQC,iC-TW8。 实例3:关于光电编码器体系,比方2048正弦周期每转,该当停止更准确的剖析,其关于旌旗灯号调理的要求仿佛其实不是出格高。可是,凡是光栅偏差普通已到达最大许可测量误差,如许分外的旌旗灯号调理偏差就无法承受了(拜见表3)。因而,因为较高的输入频次,关于细分电路的要求变得相称高。采样组件比方iC-MR是必须的。表3:与校准相干的角度偏差 白皮书 2.1 旌旗灯号调理的观点 为得到较好的细分成果,传感器旌旗灯号需求停止调理[3]。器件iC-MQF及iC-MR应用于模仿前端(AFE,拜见图7)用于旌旗灯号调理,其经由过程多个D/A转换器停止调理。与之相对,iC-TW8利用本身调理数字信号校准。 用于旌旗灯号调理的模仿前端(AFE)图7:用于旌旗灯号调理的模仿前端精细仪表放大器供给了一个粗拙的放大旌旗灯号用于旌旗灯号顺应,同时经由过程精密调节器均衡旌旗灯号差别。进一步经由过程D/A转换器在前端停止偏移校订,其能够按照旌旗灯号跟随校订。前端能够丈量旌旗灯号中的DC部门或传感器供电作为参考旌旗灯号。另外,电流控制器能够供给一个不变的条件,比方经由过程为磁阻传感器供电或为光学系统中的LED供电。此处的优势在于,假如在室温下停止调理,校准精度不会随温度的变革而变革。 枢纽特性:集成的电流/电压转换器以及电压分配器已校订偏移的仪表放大器自力的可粗调或微调的放大因子经由过程跟随偏移参考停止传感器漂移抵偿经由过程调理传感器供电实现旌旗灯号不变(总计值大概李萨如图)白皮书 数字信号校订 在模仿途径中,iC-TW8仅具有集约大和粗偏移调节器,以便使输入旌旗灯号处于A/D转换器的最好工作范围中。(拜见图8)图8:带有A/D转换器的PGA 前端以及数字信号校订器响应的,仅有数字旌旗灯号停止校订计较。能够经由过程一个精细的漂移监控器对出厂校准停止评价偏向,用于设置警报。角度位置经由过程CORDIC算法(坐标扭转数字计算法)停止计较。 枢纽特性: 可调的集约大因子(6 到45dB,3dB每步)可调的模仿偏移校订(100mV每步)数字偏移以及偏移漂移校订(244μV每步)对幅度差的数字抵偿(0.02%每步)数字相位校订(0.056o每步)观点优势两个观点都展现的优势:电源接通后,当体系处于截至形态时,模仿旌旗灯号途径已校订不变,由于传感器供电在校定时已调到最好旌旗灯号形态。在旌旗灯号途径上没有分外的延迟时间,因而能够很快地得到细分成果。关于初始化出厂校准,能够需求装备主动的丈量装备。数字校订操纵现有的运动,要末经由过程最后界说的最适宜的静态顺应,要末在使用中对其静态漂移停止持久不竭的抵偿。校准的测试装备不是必需的,且能够经由过程主动方法或按动按钮停止现场从头校准。这有利于由客户自行安装的模块化体系。表4显现关于实现的抵偿功用的器件比照白皮书 器件特性概览 iC-NQC 13位旌旗灯号调理插值细分芯片 及时增量输出BiSS绝对接口具有周期计较BiSS从机BP1,SSI   iC-MQF 可编程带RS422驱动的12位正弦/余弦插值细分芯片及时十进制增量RS422毛病保险传感器供电掌握白皮书 iC-MR 带控制器接口的13位采样连结正弦/余弦插值细分器 BiSS或嵌入式单圈和多圈处置安全监控特性 枢纽特性: 快速采样连结细分:2us,精细旌旗灯号调理,源掌握输出(ACO),1Vpp线驱动输出,并行8位单片机接口,串行接口(BiSS/SSI,SPI),I2C,12位A/D转换器(温度感到)安全特性iC-TW8 带有主动校准16位正弦/余弦插值细分器本身校准单次/不竭完善增量旌旗灯号 枢纽特性:250ksps,16位,恒定延迟时间(24us),提早规复到4us(伺服环路),二进制/十进制0.25倍至16384倍,后置AB分配器[1/1到1/32],输入频次125kHz,A/B/Z 8MHz,最小边缘间隔tMTD 31ns,主动偏移,放大,相位,按钮校准,经由过程LUT停止扭曲抵偿,旌旗灯号质量监测,利用引脚设置,I2;C,SPI,3.3V(15mA),5V白皮书 3.   总结利用差别方法对S/D转换器停止了展现,专门为插值细分,在挑选最优解决方案时应思索多个主要原则。本章的表格[4]包罗最新芯片解决方案,也能够在线下载。4.参考文献[1] EncoderTechnologiesinComparison:Magneticvs.Optical,Elektronik10/2012[2] 18Bitrelativencoder-IC,ElektronikIndustrie03/2012[3] EasyConditioningandSafeTransferofSensorSignals,Elektronik Industrie4/2010[4] ProductSelector Interpolator IC 关于iC-HausiC-Haus GmbH是一家行业抢先自力的德国制造商,为尺度集成电路(ASSP)和定制ASIC半导体供给解决方案的全球代表。30多年来,公司不断致力于在产业,汽车,医疗使用的公用集成电路的设想,消费和贩卖。iC-Haus在CMOS手艺,双极手艺以及BCD手艺方面的单位数据库专门用于设想实现传感器,激光/光学以及驱动器ASIC。集成电路组装在尺度的塑料封装内,或利用iC-Haus板上芯片手艺制造完好的微体系,多芯片模块,和连同传感器的optoBGA / QFN。更多信息请会见:http://www.ichauschina.comhttp://www.ichaus.com
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About Safer Cars FET Drive Applications
   按照IEC 61508和ISO 26262实现功用安全解决方案会影响全部工程历程从集成电路的设想到加工和质量管理。新的ISO 26262尺度的目标是在汽车的每个单一功用实现可比较的和共同的风险评价。本文概述了与微控制器平台及其周边的状况,还阐发了功率FET的功用庇护特性。     在汽车范畴将来大多数的立异将环绕新的电子系统,比方电子转向(X-by-wire),制动帮助体系(BAS),电子差速锁(EDS)和完好的电力驱动(混淆/电动汽车)。这又反过来增长了我们对电子安装功用安全的依靠,在混淆动力汽车或电动汽车到达了新的高度。到如今为止,不断提高质量想法连结在一个高等级的可靠性–虽然愈来愈庞大的设想和大量的电子子系统内置到每一个汽车。电子安全相干功用的利用,如转向,操纵,和主动制动,要求这些历程的功用安全而且不形成损伤,即便当一个简朴的毛病发作。2004年它成为须要的义务,由于IEC 61508适用于所有与安全相干的开辟。特别是关于汽车工业,ISO 26262管理着功用安全,今朝正在标准化并在将来两到三年见效。这个新的国际标准作为客观的文件, 在每个车辆功用具有可比较的和共同的风险评价。  素质安全硬件  多年来,安全的ASIC /定制芯片设想的特性是ABS和安全气囊体系的要求,是最先辈的手艺。但是,假如我们看一看在汽车电子基于微控制器的平台,状况长短常差别的。图1是一个总框图显现在汽车中的一个电子掌握单位。除了电池供电,单片机是中央单位处置当地的传感器旌旗灯号,与其他子系统通讯,并经由过程功率单位激活施行器。在安全控制器软件曾经有了长足的进步,设想加工管理,和AUTOSAR汽车电子通讯体系,汽车SPICE / CMMI和FlexRay。也有一些微控制器曾经或行将进入市场,将能够满意ISO 26262的要求ASIL D(汽车安全完整性品级D)。至于硬件设想而言,这几个方面是今朝的核心:电压监控,传感器逻辑和功用的监控,传输途径,其次是功率单位的完善驱动。传感器能够被监测经由过程硬件和微控制器软件的逻辑。关于传输链接,适宜的和谈有助于可靠地辨认而且能够改正这些毛病。功率输出级的设想是一个特别的应战,比方,在施行器的形态回读冗余能够极具本钱束缚。图1:汽车电子掌握单位整体框图单片机和掌握单位之间的接口  我们的目的是安全操纵功率单位利用来自微控制器的输出旌旗灯号。对日趋庞大的微控制器趋势于具有较低和更低的功耗,招致了较低的电源电压,较低的焦点电压,和较轻的I / O电压在输出低额定负荷。在庞大的微控制器, I / O 电压如今普通是1.8 V 到3.3 V。这抵消了不竭增加功率单位的需求–也持久作为48V车载电源,旨在低落电流和电缆消耗。电子驱动,如转向或刹车,在发作毛病时十分枢纽。这里,ISO 26262界说了四类风险(ASIL A至D),考虑到详细的安全要求和界说的最大许可的生效概率。要求经由过程手艺解决方案,低落风险。详细而言,这意味着枢纽的毛病必需被检测并自动防备毛病。功率FET完善的激活是如许十分的主要。固然也适用于FET驱动器,这是单片机和功率输出之间的次要环节。当设想FET驱动器,非常重要包罗所有的设想参数。上面是典范的: 1.毛病监测(从输出端之间毗连的GND或VCC缺失)2.驱动电源和启动特性(比方单片机I/O三态)3.需求逻辑电平转换(比方1.8–5 V至5 V或10 V)4.留意功耗,负载电流,和开关频次。  当评判一个驱动器的安全功能,次要存眷的是第一级的毛病检测和电路如何反响:1.因为印刷电路板或元器件的缺点短少接地2.电源电压缺失或颠簸3.两个输出毗连/短路4.内部突发瞬变5.输出过载和超温图2:从FMEA摘录  本次评测将主动招致一个FMEA或生效模式影响阐发。如许做的目标是为了体系地记载可能发生的工作和须要的丈量,根据IEC61508和ISO26262实现功用安全。在驱动级使用FMEA   FMEA试图形貌哪一个元件功用和潜伏的毛病或生效可能发生。生效的缘故原由和影响停止了阐发和评价,对全部产物和用户具有主要的意义。接下来的成绩要回答的是如何可能会呈现毛病–以及如何检测和避免以制止任何进一步的损伤。这些具体的阐发记载,成为任何集成电路设计计划的一个组成部分。他们固然也集成在生产过程中,集成电路测试,和产物的质量保证。经由过程举例的方法,图2给出了一个普遍的FMEA用于FET驱动器的第一页资料。防备潜伏的毛病是主要的和最重要的,是在产物和以后的操纵中具有可靠的检测。FMEA可用来肯定潜伏的枢纽毛病,他们如何肯定,以及如何制止其影响。这些信息间接影响到后续的IC设想。 FET驱动器功用安全的一个例子  这些详细的安全措施,经由过程从一个安全FET驱动器系列的IC模子举例具体注释。图3给出了一个NMOS逻辑FET驱动电路的原理图(比方,IRL44N),利用 iC-MFL作为一个驱动器。在发作毛病的状况下IC必需避免NMOS逻辑FET经由过程一个逻辑旌旗灯号激活。与所述第一级的毛病,驱动器输出必需连结在一个安全的低电平。除了基本功能,电平转换(从1.8 V–3.3 V至5 V),功率FET输入驱动器,iC-MFL的设想保护措施,避免以下毛病:1.IC短少GND或VCC2.输入开路(比方电缆断裂或单片机I/O口三态)3.两个输出短路    最严峻的状况是地或电源电压VCC的缺失,此中普通尺度的FET驱动器不能包管在输出为安全低。除了传统的VCC或电源监控,接地监控才能也被包罗在器件中。假如地的毗连被中止,没有这些步伐无明白潜伏的比率可用于内部逻辑,内部FET经由过程从IC内部电路将被激活。该器件具有两个地(GND和GNDR)。   假如一个毗连中止,监控辨认毛病并封闭输出级。假如VCC中止,输出也明白由一个值约30 KΩ的内部下拉电阻毗连到地,从而切换到一个安全的操纵模式。为了增长安全性,所有输入具有施密特触发级和下拉电流。在单片机的启动阶段,这时期所有的I/O端口三态,这些下拉电流包管了划定的FET驱动器的输入形态。FET驱动器输出是有用的推/拉电流源,此中拉侧毗连到地比推侧强。假如内部两个输出短路,此中一个驱动高电安然平静另一个为低电平,芯片输出为低,并包管一个低的电平。输出具有防过压庇护他们免受突发瞬变(18 V,100 ms)。   FMEA也能够在其他状况下利用,如PMOS-FET驱动电路,或其他输入和输出电压范畴,实现不异的单一毛病庇护。为了NMOS-FETS和PMOS FET安全驱动,器件供给可调理输出电压范畴5 V,10 V和满幅度电压。上面的例子只是说清楚明了在事情历程中避免毛病步伐,而且由IC设想间接影响。图3:安全功率FET驱动电路远景   如图所示,施行功用安全系统按照IEC 61508和ISO 26262影响全部工程历程,从集成电路设计到加工和质量管理步伐的睁开。这将一定招致各部门作为一个团队在一起事情,为项目开辟做出所需耐久的和宏大的勤奋。响应的阐发是须要的,在电子工业和其他子范畴。    固然也适用于完好的体系级别,比方转向或制动体系。这是能够预期的,安全功能将日趋成为在汽车行业和产业情况的尺度。 
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Encoder Blue
iC-Haus 使编码器显现在蓝光下利用蓝色 LED 实现一种立异奔腾的单芯片光电编码器iC-Haus 开辟用于光学定位编码器的传感器芯片,该芯片搭载了专门针对蓝光设想的光电二极管。产品图片:Encoder blue 器件体积玲珑的optoQFN 封装情势:下载文本及图片:http://www.ichaus.de/iC-Haus_Encoder_blue_newsrelease_cn  蓝光的较短波长以及较浅射入深度能够有效地提拔增量式编码器和绝对式编码器的机能,比方:分辨率,旌旗灯号幅度,谐波失真以及颤动性等。同其它波长较长的光芒比拟,蓝光在不异的间隙宽度下能够发生更小的衍射,因而能够发生更明晰的图象。     当代半导体工艺使加工愈加精密的平面构造成为能够,其能够操纵蓝光的射入深度浅的优 点提高效率。同时精密的构造也许可光电二极管利用交织规划,如许能够低落编码器正余 弦旌旗灯号的偏移。同时对光敏感区域的高添补因数能够经由过程等效几何变更来实现。  蓝光LED是白光发射的根底,汽车工业和照明手艺关于白光发射器都有着极高的需求。今朝,具有较好恒温和持久稳定性的蓝光  LED曾经能够利用,因为蓝光LED具有更高的产光率和更高的服从以及更优惠的价钱,因而今朝利用于编码器中的IR大概红光LED与蓝光LED比拟,在一定程度上就显得相形见绌了。跟着LED手艺和CMOS手艺的停顿,光学定位传感器在这方面受益显着。iC-Haus 对本人消费的高分辨率iC-PTH系列的新型增量扫描器停止优化,特别在蓝光方面。同时为该范例的单芯片编码器的集成平台注册了Encoder blue商标。  iC-PTH系列的新型编码器芯片将扫描优化和旌旗灯号插值细分分离起来,集成在极小的可用空间:带窗口的5x5 mm2optoQFN封装。经由过程对光学芯片的相位阵构造停止优化,仅用扫描最小面积  1.9 mm x 3.1 mm 和一个直径仅26mm的码盘就能够天生每转10000个脉 冲。  蓝光能够低落乐音,提高旌旗灯号对比度,同时能够经由过程提拔服从削减光学系统的电流耗损。  该芯片能够输出带零位的低颤动编码正交旌旗灯号,并经由过程4mA推挽式驱动器以单倍、 双倍或四倍细分分辨率停止准确的机器掌握。同时,在机电换向掌握中利用集成的附加三通道扫描,交换了通例的霍尔传感器。在这里,码盘界说换向旌旗灯号,调解码盘就能够很容 易使旌旗灯号与机电的极对数相适应。  零位旌旗灯号宽度和细分解析度能够简朴地经由过程芯片引脚停止挑选。许可输出频次上限至1.6MHz,如许能够实现每转10000脉冲、机电转速到达约10000rpm的机电掌握。能够激活模仿测试旌旗灯号,以易于位置对齐和测试装配校准。  扫描面积小和高敏感度有助于减小编码器本身所需能耗,5V电源只需发生仅仅几毫安的操纵电流。能够有用提拔LED的期限,特别是在机电处于较高运转温度的状况下,该IC-PT?芯片能够调理LED电流,同时对因为老化大概温度影响形成的变革停止抵偿。 iC-Haus 供给带有塑料码盘、传感器芯片和可插拔的蓝光LED的评价套,可插拔蓝光LED 可用来与利用红外光源的旌旗灯号质量停止间接比力,且对其长处停止判定。在停止体系设计时需求思索利用较高的蓝光LED的正向电压,以及在编码器中利用的质料的稳定性。  Encoder blue正由出名的编码器生产商停止集合测试和认证,而且无望近期最少在高解 析度产物方面替换今朝的红外LED和传感器芯片。欲理解更多信息,请登录 www.encoderblue.com 关于 iC-Haus iC-Haus GmbH 是一家行业抢先自力的德国制造商,为客户供给尺度集成电路(ASSP) 以及针对客户定制的公用集成电路ASIC 解决方案。30余年来全球范围内,iC-Haus 不断致力于产业、汽车以及医疗范畴的特别集成电路的使用开辟。iC-Haus在CMOS 手艺、双极手艺以及BCD手艺方面的单位数据库专门用于设想实现传感器、激光/光学以及驱 动器ASICs。   芯片装配有尺度的塑料封装,或为了完好的微体系利用iC-Haus的板上芯片封装(COB)手艺,多芯片模块,或搭载了传感器且利用  optoBGA 或optoQFN 的封装。更多信息请会见:http://www.ichauschina.com 更多成绩请详询:Horst Huse电话:+49 8762 2850                          网站:   http://www.ichaus.biz传真:+49 8762 2805                          邮箱:   horst.huse@ichaus.biz 
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Highlight Product: iC-MB4
iC-MB4iC-MB4 is a BiSS interface master, compatible with encoders using BiSS or SSI interface. The complete communication protocol is controlled by iC-MB4, and the readout sensor data can be fetched by a microcontroller/DSP. Register communication and actuator communication are also integrated in a small 5x5 mm QFN28 package (TSSOP24 also available). The main features of iC-MB4 are:Supports BiSS-C, BiSS-B, SSI and SSI extended protocolsBidirectional BiSS communication (max. 8 slaves, data rates up to 10 Mbit/s)Interface with integrated transceivers: 2 channels (TTL or CMOS) or 1 channel (RS422 or LVDS)Automatic line delay compensationSPI or parallel interface to host (e.g. microcontroller or DSP)The sensor data readout operation can be triggered automatically (AGS) or externally through pin or command. The CRC verification of the readout data is executed automatically by iC-MB4, with an error signaling in case of failure. The iC works with a single 3V to 5V supply, and is suitable for all applications where position acquisition and configuration of BiSS devices are needed, like multi-sensor systems, position encoder controllers, motor feedback systems, robotics, etc. 
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Highlight Product: iC-MHM
iC-PViC-PV: Battery-Buffered 40-Bit Multiturn Hall Encoder.  Developed for gearless multiturn encoders, iC-PV is a low-power Hall sensor based solution, which can be easily powered by a battery. Small and cost-effective, its low-consumption (10 µA from 3.0 to 5.5 V supply) makes it ideal as an alternative to mechanical gear multiturn solutions. The main features of iC-PV are:Up to 40-bit revolution countingAutomatic switch to battery power when main power failsSerial interface for connection with multiturn-enabled devices (e.g.: iC-LGC, iC-MHM, iC-MN, iC-MU)Singleturn data input for devices without multiturn interface (e.g.: iC-LNB, iC-LNG)Error signalling (configuration error, magnetic field monitoring, supply voltage monitoring)    iC-PV can also operate as a low-power (battery powered) 3-bit singleturn encoder with parallel output. With a voltage supply of 3.0 to 5.5 V and operating temperature range of -40 to +125 °C, iC-PV is suitable for industrial application.
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iC-MHM
iC-MHMiC-MHM: 14-bit Magnetic BiSS/SSI Encoder iC with Multiturn Interface.iC-MHM is an relative angle encoder, with a single-chip integrating Hall sensors, high resolution real-time sine-to-digital conversion, serial interface, multiturn interface as well as RS422 and LVDS transceivers, all integrated in a 5x5 mm QFN28 package. The main features of iC-MHM are:14-bit sine-to-digital conversion (0.02° angular resolution per 360° revolution)Integrated RS422 transceivers for BiSS/SSI communication up to 10 MHzAnalog Sin/Cos 1 Vpp differential outputUp to 46-bit resolution (32-bit multiturn + 14-bit singleturn)Error signallingiC-MHM can operate safely at 80,000 RPM with 12-bit singleturn resolution, and includes safety features like CRC proof output (up to 16-bit CRC), lifecounter and error messages in case of hall sensor errors, multiturn synchronisation problems, etc. The iC operated with 4.5 to 5.5 V power supply at a temperature range from -40 to +125 °C. The iC configuration data can be loaded from an EEPROM or through a microcontroller with SPI interface.
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Integrated optical encoder for BLDC motor feedback
集成光编码器用于BLDC 机电反应  在产业大多数的电能消耗来自大型机电和牢固速度的驱动体系。因而,能效运动控制系统应顺应将来实践负载需求使用。BLDC机电满意这一要求经由过程电子换向和调速掌握。机电磁极绕组换向在最好的转子位置的是非常重要的,用于削减电消耗当利用可变转速和负载的状况。转子位置反应可靠性是很重要的,关于运动控制系统的机能。它许可定子绕组准确的换相,最大限度地削减机电电消耗。凡是在120°相移UVW 旌旗灯号用于激活BLDC 机电驱动器的换向。差别的选项可发生UVW旌旗灯号。这能够利用霍尔传感器或开关,能够组装在绕组中或安装在一个小的PCB 上面;计较软件基于反电动势数据从定子绕组;毗连在电机轴上的光学或磁编码器;或先辈的单片光学或磁编码器芯片集成机电外壳傍边。霍尔传感器或开关普遍用于BLDC 机电,因为其低元件本钱。这种方法需求有用的算法来计较UVW,从测得的反向电动势。同时快速微处理器或DSP 需求削减执行时间和削减分外的延迟时间。这种方法的范围,UVW旌旗灯号的发生能够在快速负载变革,在低转速和在同步操纵上寓目到。硬件中检测转子的绝对位置被以为是最可靠的挑选。毗连在BLDC 机电上的光学或磁性编码器是有益的,当需求高精度静态定位,假如使用对本钱不敏感。挑选磁/光学机电编码霍尔传感器用于换向  在一个BLDC 机电利用三个别离的霍尔传感器/开关发生UVW旌旗灯号基于传感器的安装位置,无论是在定子绕组,或组装在小PCB上,0°,120°和240°,位置相对转子永磁体。在某些状况下,一个磁极环毗连到轴能够用。图1 的右边显现了三个霍尔传感器/开关的机器位置,用于UVW旌旗灯号的发生。UVW旌旗灯号定位精度与关的转子实践位置取决于安装公役与共同霍尔传感器/开关的灵敏度和稳定性。磁场变革许多,因为超温,转子速度和操纵期限(永磁老化),位置偏差很容易累加+ / - 3°或更多。另一种办法利用四个集成霍尔传感器而且旌旗灯号调度天生正弦/余弦旌旗灯号,此中在360°动弹角度位置是持续可用的。图1的右侧显现了霍尔安插。一个小的永磁铁直径在4-6mm毗连到转轴,经由过程集成霍尔桥收罗发生轮回变革旌旗灯号。传感器安装许可发生一个差分正弦/余弦旌旗灯号,对一般的磁场是不敏感的。正弦/余弦旌旗灯号然后能够经由过程一个正弦-数字转换器转换为绝对位置值。这类插补经由过程计较正弦值除以余弦值的反正切。它供给了转子的绝对位置,可设置6~12位分辨率。图 1: BLDC机电位置检测的挑选用于换向  当代混淆旌旗灯号集成的研究进展,让霍尔阵列加上所有的正弦/余弦旌旗灯号调度和插值用于绝对位置,可以在一个编码器IC集成。替代三个别离的霍尔传感器/开关,一个单一的5x5mm封装能够组装在同一个PCB上(参图1)。该Z 旌旗灯号标记转子的zero位置,许可从ABZ旌旗灯号以简朴的办法计较机电的绝对位置,在机电掌握和运动控制系统。从绝对位置也能够发生增量ABZ旌旗灯号可用于监测快速位置变革,以十分低的提早。图2显现了上/下AB旌旗灯号编码,用于增量操纵。当机电的标的目的反转AB旌旗灯号改动其相移。该Z旌旗灯号标记转子的zero位置,许可从ABZ旌旗灯号以简朴的办法计较机电的绝对位置,在机电掌握或运动控制系统。用正弦/余弦到UVW,插值单位的换向旌旗灯号能够发生两个,四个或多个磁极机电范例。在这种情况下,每一个换向旌旗灯号偏移了66°相位。它能够间接掌握BLDC驱动单位用于块换向。它也能够经由过程机电控制器用来发生正弦波换向。一个集成的单芯片磁编码器凡是有多输出选项,用于机电控制器或初级运动控制器。但停顿远落伍于当前的需求。图2: 经由过程正弦/余弦发生UVW和ABZ提出了经由过程单芯片编码器集成单芯片编码器一体化的停顿,使一个完好的“片上体系”具有多个输出挑选用于BLDC 机电。图3显现了BLDC 机电反应选项,以iC-MH8作为一个例子。在顶部的UVW 其他旌旗灯号的输出选项设置,比方绝对位置经由过程SSI / BiSS接口,ABZ增量和模仿正弦/余弦旌旗灯号。该芯片包罗一个霍尔阵列,模仿旌旗灯号调度,数字正弦/余弦插值,偏差监控,自动增益控制,多编码器的输出格局,UVW机电换向输出,数字设置,线驱动才能,和片内编程。霍尔桥旌旗灯号调度和放大经由过程PGA自动增益控制来抵偿差别的操纵条件,如温度,电源电压或磁场的变革因为温度或老化。图3: 绝对磁编码器机电掌握带输出选项  芯片上的正弦/余弦旌旗灯号放大到1 Vpp,而且经由过程一个差分模仿输出驱动器,用于内部监测或自力的插补。他们也被用于12位及时正弦数字转换器/插补器,以一个十分低工夫提早,小于1μS。12位供给了一个小于0.1°的分辨率。一个绝对位置可读出经由过程串行SSI(同步串行接口)或BiSS接口(双向同步串行接口)的运动控制器。一个开放尺度的SSI / BISS供给高速串行接口,也用于生产线设置。假如需求,集成的RS422 线路驱动器撑持长电缆到机电或运动控制器。ABZ旌旗灯号以2MHz的频次更新而且延迟时间小于1μS。零位可编程256 步(114°)用于增量,192 步(118°)用于UVW接口。也很重要的是要有设置和调度模仿旌旗灯号的才能。这需求一个高质量编码器输出旌旗灯号。挑选BLDC 机电换向磁极设置,可用于各类差别的机电装备范例。可调设置存储在编码器芯片的RAM而且可以编程到片内非易失性ROM 中,上电后可读。光集成也能够  磁性编码器芯片可以更好的用于十分刻薄,尘埃和严厉的情况。但是光单片编码器芯片带换向输出经由过程光学系统集成一样变为能够。其机能更高一些,但比照表白,两种手艺齐头并进。图4显现了两个单芯片光学编码器带增量和UVW输出。这里的分辨率界说是码盘肯定的,而且利用三个光学传感器用于发生UVW。机电的极对数界说是码盘设想肯定的。比方,四个光电二极管阵列能够供给高达20,000CPR用一个直径33.2mm的码盘。特别的封装如optoQFN契合这个光学解决方案需求。如今的混淆旌旗灯号集成才能能够供给可靠、高度灵敏单片编码器芯片,而且可设置磁编码器反应选项具有12位分辨率。这与传统的霍尔传感器/开关体系相比较,具有高机能集成到机电壳体。在光学编码器带有集成的UVW输出挑选,也是单芯片解决方案的发展趋势。这些趋向撑持加强机能提高机电电子换向的能量服从,经由过程最好的机电反应解决方案。图 4: 光学单芯片机电编码器芯片带UVW换向    
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IC-HAUS Driven Application Program
IC-HAUS 驱动中的使用计划-----------涉及到IC-HAUS电源管理iCs、编码器iCs、24V通讯电缆驱动iCsIC-HAUS驱动中的使用计划在产业和自动控制范畴为客户供给灵敏的电源解决方案,并且供电系统的电压范畴广大。能够使用在产业传感器、扭转编码器、直线编码器等。论文在引见IC-HAUS的驱动计划前先简介IC-HAUS电源管理iCs。一:IC-HAUS电源管理iCs IC-HAUS电源管理iCs统共有6个型号,能够分为三个范例:IC-DC,IC-JJ,IC-WD系列。IC-DC在计划中作为电源芯片IC-JJ的特性以下:供电电压VBAT范畴6 to 16.5V。在输入电压不稳定的状况下可以不变输出必然工夫---自给功用。静态电流很小,30μA阁下。兼容TTL-/CMOS输出模式。12V/30mA三态输出。欠压检测,单线串行总线,看门狗检测功用,ESD庇护。 IC-WD系列的特性以下:输入电压范畴8-36 VDC服从十分高的降压变换器内部集成了开关晶体管和续流二极管经由过程内部电阻调理停止电流;100 kHz内部自带集成的振荡器两路降压调理输出别离200mA/25mA输出电流十分低的纹波;ESD庇护;温度范畴在-40 to 85°C之间SO8和DFN10两种封装格局在PCB布线的时分需求极少的空间二:驱动中的使用计划如上图所暗示的是DC/DC变换器iC-DC的使用。输入电压的范畴是在4.5V到32V之间。VCC2给6通道增量光学编码器iC-LTA/iC-PT供电,VCC1给3通道差分线驱动器带集成阻抗匹配的器件iC-DL供电。这类供电方法使传感器件和电平传输器件之间做到了有用的断绝。iC-DL器件的过压和过温报警经由过程TNER引脚进入iC-DL。经由过程这类方法将iC-DC的错误信息和iC-DL的欠压和过温监测联络起来。NER管脚将供给两个芯片的错误信息。    图例电路操纵了iC-DC自己固有的反向电极庇护特性。ZD1, ZD2, D2 to D13 和 电阻 R3构成的庇护电路能够避免任何情势的过压输出。工程师在设想这些庇护电路的时分能够按照本人的经历,没有特定的要求。详细设想规格参照官网阐明。输入电源经由过程电源管理IC内部的二极管接在IC-DL的管脚VBx上供电,非常便利。  iC-LTA/iC-PT是6通道增量光学编码器,能够使用在直流无刷电动机和产业驱动上。实测输出波形以下所示:能够看出波形对称性很好,波形结果非常幻想。波形输入到24V通讯电缆驱动IC-DL的输入口,IC-DL输出经由过程通讯电缆输入到100米外的PLC。IC-DL的特性:6通道限流防短路推挽式的驱动3路差动通道的挑选集成了30至140欧姆的电阻;供电电压范畴很宽在4到40V之间。200mA输出电流;输出饱和电压很低;兼容TIA/EIA standard RS-422。总线输出三态开关;转化无延时上升斜率很高。内部施米特触发器,下拉电阻;TTL and CMOS电平兼容;防压高达40V。RS‐422(EIA RS‐422‐A Standard)是Apple的Macintosh计算机的串口毗连尺度。RS‐422利用差分旌旗灯号,RS‐232利用非均衡参考地的旌旗灯号。差分传输利用两根线发送和领受旌旗灯号,比照RS‐232,它能更好的抗噪声和有更远的传输间隔。在产业情况中更好的抗噪性和更远的传输间隔是一个很大的长处。      RS‐485(EIA‐485尺度)是RS‐422的改良,由于它增长了装备的个数,从10个增长到32个,同时界说了在最大装备个数状况下的电气特性,以包管充足的旌旗灯号电压。RS‐485是RS‐422的超集,因而所有的RS‐422装备能够被RS‐485掌握。RS‐485能够用超越4000英尺(1200m)的线停止串行通行。      RS485是从RS422开展起来的,接纳一对差分线A和B,还有一个使能旌旗灯号能够使A和B处于高阻态。      RS485尺度满意RS422标准,以是RS485驱动器可在RS422网络中使用。RS-485 的数据最高传输速率为10Mbps。可是因为RS-485 经常要与PC 机的RS-232口通讯,以是实际上普通最高115.2Kbps。又因为太高的速率会使RS-485 传输间隔减小,以是常常为9600bps 阁下或以下。iC-DL的封装如下图:IC-DL能够监控VB、VCC和芯片温度;当呈现毛病的时分让所有的输出级都呈高阻形态,然后置低NER。除此之外,还能够监测VB1, VB2 和VB3的电压差,当绝对误差超越0.75 V时发生报错旌旗灯号。 
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Using iC-haus interface chip microcontroller access to the industrial world
接纳iC-haus接口芯片把微控制器接入产业世界产业使用接纳嵌入式微控制器时需求出格存眷现场卑劣的噪声情况。从供电电压低至+1.5V大概+3.3V到24V工业界,需求认真设想和决议计划专门的解决方案来到达安全和不变的事情。上面的文章形貌差别的应战和设想思索以及能够的解决方案满意最大能够的功用安全和可靠性。 文章形貌的内容以下:工业界 — 一个差别的世界有哪些设想应战电平转换器和驱动器输出旌旗灯号安全接纳分立元件仍是 ASSP I/O 接口处置24V输入旌旗灯号噪声驱动激光二极管/LED哪些地方需求省电提要1)工业界 — 一个差别的世界 自从在1970年月创造微控制器以来微控制器趋势于更多的公用衍生和更多的功用和较低的手艺门坎。集成更多功能,更大存储器以及低功耗。 关于一个给出的使用,每个人都在寻觅“最好的事情形态”到达最低的本钱,最小的空间和最小的功率耗损。为到达这些需求而接纳一个新的单片机而辩说。最初的结果是微控制器的供电电压连续低落,在某些状况下内核事情电压低至0.8V,I/O接口电压低至+1.5V。 但是,在产业应用领域,大多数供电和逻辑电平照旧是+24V。利用+24V供电和逻辑电平顺应产业应用领域的噪声和卑劣的事情情况。因为这个缘故原由,优良的电子抗干扰性需求接口耐受高电流尖脉冲、磁滋扰、静电放电等等。大多状况下微控制器和工业界的电流大概电压是一个10倍的干系。但是,我们要处理的是安培级大概是伏特级的成绩,而不是毫安级大概毫伏级的成绩。这就为硬件设计者提出了一个应战,在两个范畴断绝和转换旌旗灯号电平。这意味着从转换低至1.5V的单片机逻辑电平到+24V的电压摆率在输出大概其他标的目的的输入。 利用微控制器在嵌入式使用,比方,加工掌握、机器人、自动化装备等等。意味着在某种水平上认真地设想接口,那就是可靠和考虑到安全事情。也有很多尺度适用于某些方面的功用安全,比方IEC 61580和EN 60204-1。 2)有哪些设想应战 就产业情况的素质,应战每一个设想的是上面的这些需求: 高电压摆率跟着快速的dV/dt大概dI/dt转换惹起的输入旌旗灯号和输出旌旗灯号的穿插滋扰接地回路因为体系的散布参数而改动接地电平体系大概软件生效惹起的鼓励端破坏(比方,功率输出级) 因为这些缘故原由,在设想微控制器和+24V工业界之间的接口时下面的这几点需求思索: 微控制器需求多高的电平转换给输出?微控制器需求多高的电平顺应于其输入?针对硬件大概软件的毛病如何庇护输出级?数字的和/或模仿的毗连需求什么样的滤波?产业I/O和微控制器之间需求强迫的断绝?多大的功率上升和降落举动需求被思索?哪些生效需求被监控以及如何监控?哪些地方是高功率耗损惹起的热斑(比方,高电流大概高频次)? 3)电平转换器和驱动器输出旌旗灯号安全   最后思索的是着眼于微控制器的I/O端口逻辑电平,然后是明白输出需求的电流和电压。比方,驱动高电流阻性负载,像加热器大概执行机构,需求一个逻辑电平转换和功率三极管大概FET功率前置-驱动器。图1所示的例子是转换+1.8V供电的微控制器逻辑电平,经由过程前置-驱动器,掌握一个高电流+24V FET。来自微控制器的逻辑电平,这个FET撑持的切换负载电流大于10安培。图1所示的另一个挑选是毗连一个高边开关,比方,iC-DP,在36V供电时撑持负载电流高达200毫安。  由于在上电时微控制器的I/O端口曾经毗连到输入,需求出格防备这里。为了制止在这个时期浮动的输入电平转换,假如下拉电阻没有集成到器件内部,需求毗连附加的下拉电阻,比方iC-MFL。  另一个需求思索的处所是输出端短路的生效-安全庇护监测,监控VCC电压、地和芯片温度。在实践使用中,输出端生效将会惹起破坏大概会损伤到使用者,大概破坏高贵的装备,大概需求一个FMEA阐发来满意安全标准(比方,IEC 61508)。  这需求在全部体系级、板级和芯片级做FMEA阐发。对于此电平转换和前置-驱动器iC-MFL,FMEA安全电路曾经集成到芯片级,并且包罗第二个地毗连和特别的地监控。  关于iC-MFL,假如第一个地毗连丧失(第一级生效),监控器肃清所有的输出到一个界说好的低电平,封闭所有的输出功率级。大概微控制器经由过程一个低电平加到EN输入封闭这个电平转换器,一样的操纵会施行,输入开路以及输出短路。图1:电平转换和驱动功率输出  iC-MFL的输出级设想成最大输出电压为+18V。其他范例的驱动器,像iC-MFN,可用来处置差别的输出电平而且能够间接供电从+24V到高达+40V。在很多嵌入式体系一些数目的输入和输出因为差别的机器配置能够差别以及在I/O端口需求一些差别的组合。 4)接纳分立元件仍是ASSP I/O 接口 ?   I/O模块化能够利用差别的办法。一个解决方案是板级计划,挑选一个差别的I/O模块大概PCB,大概是在嵌入式电路板的芯片级计划。也能够是一个FPGA和分立元件构成的输入或输出级,大概利用公用的ASSP。这些特别的设想适用于灵敏的和可编程的I/O设置。  在嵌入式机器大概机器人使用,传感器和执行机构有时候仅数米远。假如它们接纳屏障双绞线电缆毗连而且在中央接地,那么接地回路凡是对输入/输出体系不会有成绩。因而,在许多状况下,电断绝(比方,经由过程光电耦合器电流断绝)是不需要的。这关于体系设计者而言能够削减I/O端口的本钱以及增长灵活性。  另一方面,数字I/O接纳+24V逻辑电平被用来毗连开关、数字传感器和在输入侧经由过程长电缆停止低速串行通讯。+24输出也被用于驱动执行机构,比方,继电器、电磁线圈、机电和指示器,比方,灯胆大概LED。关于高速串行传输(比方,SSI/BiSS编码器)在一个高噪声的情况,RS422也凡是被利用高出超越100米的间隔。为了到达可靠的事情,利用生效监控,在输入端出格思索以下:I/O端口能够没有可靠毗连检测开路、短路和毗连断开供给滤波器抑止噪声、穿插滋扰、尖峰大概机器开关跳动检测已界说的旌旗灯号传输用来发生微控制器中止 在设想输出端时思索一样主要,比方:耐受和检测短路,检测超温限定灯具发生的浪涌电流以及抑止线圈封闭时发生的电压尖峰撑持脉冲输出用于闪灼或功率低落  切换负载利用高边开关输出是较多的首选办法,断开大概接地负载不能影响+24V体系供电。监控差别的电路生效,比方,+24V供电不敷,一些丧失地线毗连以及由驱动器超温惹起的临界状态的使用。具有回读输出端口的选项,大概丈量I/O端口的模仿电平用于更具体的诊断对到达功用安全长短常有效的。丈量I/O接口模仿电平的办法也用于+24V输入端口。  很多数字功用需求组合的I/O端口,能够在FPGA里做这些端口,但是模仿功用、+24 I/O 以及毛病监控需求利用分立元件实现。一个公用的、可编程的以及组合的+24V I/O解决方案如图2所示。这个例子是基于ASSP,它经由过程一个并行总线大概串行SPI接口毗连到微控制器,险些各类微控制器都能够如许利用。   在此使用中电源和地是需求断绝的,iC-JX能够通用一个断绝的(比方利用光电耦合器)SPI接口毗连。因为利用了很少的断绝线缆,这是一个较着的本钱优势计划。这种情况下,iC-JX的逻辑供电能够从+24V经由过程一个电压稳压器供给+3.3V,和+5V给数字和模仿电路。  iC-JX也供给所有I/O端口的回读功用。另外,集成的16通道10位A/D转换器撑持端口察看,比方,察看+24V模仿输入用于诊断功用。 这些特性供给了功用安全、提高了在线保护才能以及生效检测。当接纳一个遥控诊断功用时这会明显的削减保护本钱。  关于电压调整器,iC-WD大概iC-DC能够发生两个输出电压用于小的I/O子系统,它分离了一个开关模式的DC/DC转换器和一个线性稳压器。这会减小模仿电路的纹波以及连结电源本身的低消耗。图2:松散的通用I/O和光学断绝  关于这个电路另外的安全性,假如一个毛病形态在微控制器内部发生,一个内部看门狗电路也能够监控微控制器能否有用以及禁用所有的16个I/O端口。5)处置24V输入旌旗灯号噪声   在输入旌旗灯号噪声方面,数字的大概模仿的滤波器需求制止被微控制器毛病的读入,关于数字信号,iC-JX输入具有内建迟滞数字滤波选项。模仿输入旌旗灯号能够经由过程分立元件的滤波器大概内建的比力强滤波功用,比方,连结、迟滞大概RC电路。图3所示的是iC-HC的连结功用影响输入噪声。图3:集成滤波的输入噪声滤波功用此计划是典范的快速丈量输入电平以及内建电平转换用于微控制器的输入。此供电电压和差分输入电压能够高达36V。省电方面,iC-HC比力器能够经由过程使能输入切换到“zero功耗”模式。6)驱动激光二极管和LED   利用一个微控制器驱动激光二极管需求恒流源和尖峰开释开关来制止破坏高贵的激光二极管。取决于电流和切换频次,差别尺度的驱动器许可均匀电流掌握(ACC)和/或平均功率掌握(APC)。图4所示的是集成解决方案iC-HG驱动三只激光二极管(大概LED阵列)带可调理的恒流功用。图4:驱动RGB激光二极管/LED高达1安培的电流  上图是典范的RGB光源应用于差别的产业范畴,比方激光模块。当设想和测试快速激光驱动电路时,请看另外一篇文章,“设想和测试快速激光驱动器电路”。7)哪些地方需求省电因为产业旌旗灯号是高电压摆率,功率耗损就成为一个值得留意的成绩。关于输出级,当转换频次降低时将会有超温征象呈现。一个典范的例子是24V线驱动用于串行通讯子系统。  一个可选的计划处置这个问题的办法是存储没有终端婚配的传输线反射的旌旗灯号能量在电容里,而且利用这个能量为驱动器供电。这个办法能够节流高达50%的器件耗损能量,在转换频次小于250KHz时能够削减3个瓦特的器件热耗损。因而,增长了稳定性和削减了散热需求。iC-HX是一个24V线驱动器撑持这个功用,仅需求增长一个电容。测试成果显在传输速率为200KHz时,iC-HX的外壳温度从100℃减小到70℃。  减小线驱动的功耗是一个省电的例子。因而,所有运转在高频次和高电流的体系的各个部门都该当认真评价它们潜伏的功率耗损(比方,利用低RDSONFET)。  驱动继电器和电磁阀也是一个特别的状况,因为继电器(电磁阀)的吸合大概开释形态的特性决议的。考虑到这个特性,驱动继电器和电磁阀需求认真思索电路的级别。吸合工夫在10-100毫秒时吸合电流需求大于两倍的事情电流,取决于继电器大概电磁阀的特性。超越吸合工夫后电流能够削减最少三分之一。这能够接纳分立元件的RC网络大概脉宽调制电路(PWM)。当可靠吸合以后改动占空比大概改动频次。PWM经由过程内建FPGA电路序列大概利用一个微控制器PWM输出大概利用一个ASSP器件处理这个需求。图5:集成驱动继电器(电磁阀)省电解决方案  假如也需求继电器大概电磁阀的监控功用,能够接纳一个公用的ASSP。图5所示的iC-GE电路用于驱动继电器大概电磁阀,间接从36V供电,兼容典范的TTL输入电平。此器件仅需外接RHOLD和RACT电阻界说所需求的吸合和连结电流。这个集成解决方案实际上改动电流许可不异的继电器能够利用在差别供电电压的使用。为了到达这点,差别供电电压时,PWM输出的占空比和频次需求校准。  这个公用的ASSP解决方案也集成了箝位二极管和维修唆使。它也监控线圈的电流、欠压和超温。假如一个毛病发作,LED灯会闪灼,也能够用来作为一个中止给微控制器。如上所述,当驱动继电器和电磁阀时,减小器件的功率耗损是能够的。经由过程特别的思索,一个板级的解决方案可在项目设想阶段处理。7)提要  如本文所述,当毗连微控制器到工业界时有很多特别的设想思索。普遍的利用微控制器作为嵌入式解决方案用于汽车、机电以及机器控制系统。当要毗连到工业界时设计者需求思索特别的需求。幸亏,iC-Haus公用的产业ASSP解决方案处理了这些承担,以及处理了设计者在板级的很多成绩。 
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Design and Test of Fast Laser Driver Circuits
设想和测试快速激光驱动器电路自从 Theodore H Maiman 在50年前创造激光器以来,激光被普遍应用到各类手艺范畴,比方通讯,工业生产,以及传感器和丈量装备。通讯行业存眷的是高达GHz范畴的高速传输频次,工业生产次要存眷的目的凡是是高速的超短范围内纳秒级脉冲光功率。在传感器和丈量使用的应战是设想快速激光驱动器电路,这是一个十分苛求的使命。上面的文章形貌激光驱动器电路设计,PCB规划和光学丈量注意事项,以及设想一个脉冲宽度短到2.5ns的幻想解决方案。目次集成激光驱动器解决方案快速激光驱动器电路设计注意事项规划要求丈量激光脉冲4.1)从示波器到光学仪器4.2)从计算机到光学USB仪器设想查抄提要1)集成激光驱动器解决方案 传统的激光二极管驱动器电路凡是利用分立元件,用于低成本和低机能使用。集成激光驱动器的优势解决方案是: 1.       提高输出功率的稳定性(1%或优于1%)2.       削减板子空间(削减80%以上)3.       毛病监控4.       较好的静态机能5.       提高了可靠性/MTBF 用于快速开关,集成驱动器是必需的,由于减小PCB散布电感和分布电容是许可更快速旌旗灯号变革的次要办法。2)快速激光驱动器电路设计注意事项   用于丈量和传感器范畴的激光器光源凡是是半导体二极管激光器,光学输出功率从几个微瓦到几百个毫瓦。集成电路可便利地和安全地掌握半导体激光二极管,光谱笼盖全部可见光到红外光范畴。最新研发的全范例集成激光驱动器解决方案撑持开关频次高达155 MHz以及激光驱动电流高达300 mA。图1所示的原理图是iC-NZN的使用电路。它的事情电压从3.3V 到5.5V,能够去驱动N,M和P型激光二极管带大概不带监控二极管。 图1.全范例激光二极管驱动器电路  撑持两种事情模式,主动功率掌握(APC)和主动电流掌握(ACC)。光学输出功率各自差别。驱动电流由电阻PMD/RMD设置,如上面图1所示。假如接纳一个适宜的PCB规划,脉冲宽度能够到达小于3.5ns以及脉冲上升沿和降落沿时长(tr/tf)为1.5ns(最大)。在这种情况下该当接纳LVDS输入旌旗灯号替换TTL电平来削减EMI。iC-NZN的特性是供给了一个低边输出(专门为N型激光二极管优化),iC-NZP的特性是供给了一个高边输出(专门为P型激光二极管优化)。为了庇护激光二极管,特别是在APC模式,经由过程管脚VDDA的最大驱动电流能够由电阻RSI来限定。  关于更高功率的激光脉冲,比方电流开关iC-HG,供给一个集成的解决方案。它的特性是可供给6个带尖峰开释的电流开关,每一个开关切换电流为500mA,并且这些开关能够并联起来到达3A DC 电流。脉冲宽度能够低至2.5ns,峰值电流可达9A。最大开关频次200MHz,上升和降落沿时长1ns(最大)。最大占空比取决功率耗散和iC-HG的散热状况。 图2:CW驱动电流可达3A,脉冲驱动可达9A的激光驱动电路   输入EN1和EN2利用LVDS模式带100欧姆线路终端电阻。激光器电源电压(最大12V)由两个低ESR钽电容缓冲以及利用两个瓷片电容停止RF滤波。iC-HG监控LVDS输入旌旗灯号,假如幅度低于50%,会在管脚NER发生一个毛病旌旗灯号,电源电压和芯片温度也被监控。当欠压和过载时NER旌旗灯号也会发生。每一个通道的电流能够经由过程掌握CIx的电压来设置。它也能够被用来做模仿调制。最大调制频次典范值2MHz,CIx的输入电容是调制频次的限定身分。3)规划要求关于十分短的激光脉冲,激光驱动模块的规划是抉剔的。因为快速开关的瞬态历程,当设想PCB时传输线路低电感是要记着的枢纽。图3a所示的是一个iC-HG高速驱动模块的例子,图3b是规划的细节。推荐规划指导方针以下:连结从驱动器到激光二极管的线路和回路尽量的短(每一个mm都要思索);安排储能/旁路电容在驱动器IC电源和地线四周;挑选低ESR电容(利用两个电容并联来减小ESR);分隔AGNDx和GND大面积铺地(仅在大众地处毗连);确保DFN封装的散热PAD的散热图3a:高速激光驱动模块 图3b:高速激光驱动模块规划 4)丈量激光脉冲 4.1)从示波器到光学仪器为了激光二极管脉冲的光学丈量,需求一台高速示波器和一个附加的高速光电接收器。此光电接收器该当在相干频谱范畴具有高灵敏度以及尽量宽的带宽,从DC到GHz范畴,以便激光脉冲的幅度和快速脉冲的边缘一样能够被丈量。图4a所示的是一个典范的光学丈量安装,利用iC212高速光电接收器作为示波器的一个适配器。在这个例子里,利用一个约莫12.5ns的40mW的激光脉冲发生器,脉冲幅度和上升沿时长能够利用示波器丈量。示波器需求一个适宜的高模仿带宽,事情频次也要到GHz范畴。图4b所示的是光学脉冲响应。为了知道精确的激光脉冲外形,仅有一个电气丈量激光电流是不敷的。因为激光二极管的特性,丈量成果会大差别。因而必需丈量激光二极管的光学输出。这凡是是经由过程利用一个扩大通例实验室设备用于电子丈量。能够的办法有扩大通例示波器大概实验用PC来丈量光学的激光光束。图4a:激光二极管模块丈量安装                图4b:光电接收器iC212的激光脉冲利用iC212光电接收器                            丈量成果 iC212是专门为此类丈量而设想的光电接收器,它是第一个此类安装,分离一个带宽范畴从直流到1.4 GHz的宽光谱灵敏度,波长从320至1000nm(见图5)。它能够丈量持续波和脉冲光功率,瞬态低至280ps。图5:光电接收器频谱灵敏度  iC212在波长760nm处的增益因数是1.625V/mW。这许可光学功率丈量低至子毫瓦范畴。激光脉冲的上升沿和降落沿时长能够间接从示波器读出。然后光学功率能够由丈量获得的幅度除以相干波长的灵敏度得出。图6:丈量功率图6所示的示波器丈量波长为635nm。灵敏度由图5得出,在635nm处,S=1.34V/mW。光学功率有上面的式子计较,此中,U是从示波器读出的幅度。Popt(iC212) = U / S = 0.803 V / 1.34 V/mW = 0.60 mW除了激光二极管和激光模块的光学丈量,IC212也可用来丈量玻璃纤维传输线,光学传输工夫,照度大概激光体系的光学触发大概毛病检测测试。4.2)从计算机到USB光学仪器  另一个挑选是iC227数字示波器,经由过程USB毗连到尝试计算机。它是一个十分快速和准确的双通道8GHz次第采样示波器,基于微控制器和高速ECL差分电路。微控制器颠末断绝的全速USB接口通讯,全速速率12 Mbits/s。次第工作范围是由在触发和采样电路之间插入增量时延完成。ADC转换跟着一个触发变乱开端以10皮秒增量采样。图7所示的是iC227设置成 4 GHz双通道示波器的功用道理。毗连到iC212的被测部件来组成一个完好的光学计算机仪器。iC227次要特性以下:8 GHz带宽触发输入带宽2 GHz时基范畴25ps到100us垂直12位分辨率时基精度1.5%FS+/-10ps垂直精度跟着CH1/CH2输入 3%FS最小触发频次10KHz垂直刻度10到1000 mV最大输入采样电压2Vpp,触发输入4Vpp图7:USB示波器功用道理 由采样道理可知,IC227仅接纳反复旌旗灯号事情。然后,需求一个数字脉冲发生器来完成测试安装。图8所示的是iC149脉冲发生器。它发生脉冲宽度从1到64ns,步长增量0.25ns。牢固频次1MHz以及供给LVDS和TTL输出。管脚毗连兼容iC-HG和iC-NZN/NZP评价板。图8:脉冲发生器管脚毗连合用iC-HG/NZN/NZP评价板脉冲宽度可由两位二进制码扭转开关设置。举个例子阐明,一个完好的测试安装如图9所示。  它由一个光学测试台构成,包罗iC-NZN评价板和脉冲发生器iC149。接收器方iC212光电领受被用来和iC227一同事情,iC227带宽设置为8GHz,iC212光电接收器直接连接到通道1。”Input via Trigger“复选框必需连结未选。图9:光学丈量接纳计算机USB光学仪器iC212光电接收器输出直接连接到”SAMPLER IN1“”Input via Trigger“复选框必需连结未选。5)设想查抄关于高速激光驱动器设想,推荐重视思索以下项目:PCB板规划见以上第3项示波器带宽要充实思索快速跃迁和过冲iC-HG在LDKx的过冲输出不该当超越最大值12ViC-NZN在LDK的过冲输出不该当超越15V,正常值为12V6)提要新一代基于iC-HG的激光驱动器电路可以发生高功率激光脉冲,脉宽低于3.5ns。为了在相干使用中能准确到达这个目的,需求优化PCB设想来减小散布电感。需求专用工具来丈量光学输出的上升沿和降落沿时长。光电接收器iC212,脉冲发生器iC149和数字USB示波器iC227是这些丈量装备新的挑选。   
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Single-chip encoder to improve the performance of motion control applications
接纳单芯片编码器提高运动掌握使用的机能     典范的尺度封装编码器是很多运动掌握使用的反应装备,可是提供给最终用户的很多设置是有限定的。一个替换和面向使用的办法是操纵更高集成度的和智能化的传感器手艺基于一个单芯片的编码器设想。这些供给了一个高度灵敏的和可设置的挑选,关于那些需求可以微调编码器输出而提高整体系统性能。 上面的白皮书形貌了接纳单芯片编码器计划提高运动控制系统的机能。目次:1) 提高运动掌握使用的机能       P.32) 单芯片编码器设想办法       P.43) 单芯片编码器的范例和选项     P.64) 单芯片编码器提高机能的特性     P.85) 择要               P.131)   提高运动掌握使用的机能 在运动掌握使用中,可提高运动反应回路的机能来加强系统性能。扭转和线性编码器供给这个反应来及时陈述速度和位置。 比方,能够由上面的方法提高体系的运动掌握机能:* 提高定位精度* 较高的运转速度* 提高体系服从* 提高可靠性和可重复性比方,能够由上面的办法实现如许的性能指标:*体系和部件装配校准*及时设置调解*削减机器公役*增加机器定位调解*预防性维修调解  固然施行许多上面这些办法来提高体系的机能是可取的,但关于新的设想大概现有的设想不老是有可能的。并且,实现这些改动会影响体系设想的复杂性,可制造性,外形尺寸,本钱和上市工夫。但是,提高运动掌握的反应有助于提高系运动体系的机能,让我们胪陈一个编码器设想,能够削减这些身分大概完整消弭它们2)单芯片编码器设想办法  思索图1的尺度机电设置。这是一个尺度封装编码器被装到一个无刷直流电机来供给运动掌握使用的位置反应。一旦此机电设置被毗连到驱动使用体系,会有机器和电子的调理范围。大部分状况下,这是可完整承受的,可是对那些需求较高机能的体系,必需要求更多的编码器设置掌握来满意设想目的。图1:BLDC直流无刷机电毗连自力封装编码器 留意:Comm 是换向旌旗灯号,ABZ是增量输出旌旗灯号,ABS是绝对位置输出  如今来引见另一种单芯片编码器解决方案如图2所示。利用这个设想办法,一颗编码器芯片,利用一个现成的外壳解决方案。因为这个高集成度单芯片编码器芯片,只需求这个芯片自己再加上几个分立元件便到达所有的要求。另外,参考电路板设想和规划凡是可从编码器IC制造商处获得。 如图2所示,自力封装编码器计划被单芯片编码器设想代替,这个例子是一个iC-MH磁编码器IC。接纳此范例设想可经由过程一个数字接口来调解编码器的设置。 图2:直流无刷机电毗连基于单芯片设想的编码器 留意::Comm 是换向旌旗灯号,ABZ是增量输出旌旗灯号,ABS是绝对位置输出Sin/Cos是模仿正弦和余弦输出,Config是编码器设置   如图中所示,编码器芯片感知电机轴扭转的办法是经由过程一个径向磁化的圆柱状磁铁。此磁铁安装到贯穿的电机轴,许可间接检测机电的位置和速度。接纳单芯片编码器设想有可能供给增量输出,正弦/余弦模仿输出[4],以及为设置和绝对位置数据读出的数字串行接口。 3)单芯片编码器的范例和选项   磁编码器和光学编码器如图3所示。准确挑选其中之一会严峻影响体系的机能。比方,选用磁编码器能够更好的顺应卑劣情况,以及装配较简朴,凡是它的分辨率和精度低于可比的光学编码器。思索图4的单芯片编码器选型指南。经由过程比力每一个编码器IC的多个特性,这将有助于为使用找到最好的解决方案。图3:单芯片磁编码器IC与磁铁以及单芯片光学编码器IC与LED和码盘图4:单芯片编码器选型指南输出格局:如图5所示,单芯片编码器如IC-LNG供给差别输出格局而且有许多是能够同时利用的图5:iC-LNG光学绝对编码器IC展现很多可用的编码器输出格局   关于某些编码器器件,比方iC-MH8,有一个源码开放的串行接口BiSS,它许可高速串行接口读取设置和绝对位置。有关更多的BiSS信息在BiSS的网站上能够找到。[1]4)单芯片编码器提高机能的特性   如图7所示,此中一些特性包罗模仿旌旗灯号调度,数字正弦/余弦细分,毛病监督,自动增益控制,多种编码器输出格局,BLDC机电换向旌旗灯号输出,数字设置,线驱动才能以及在体系编程性。图7:iC-MH8磁编码器IC方框图       这些设置能够经由过程串行接口编程,许多编码器IC供给一个计算机图形用户界面东西许可简朴和及时的交互编程此器件。一个计算机适配器用来做电路板上的编码器IC的接口,然后这个适配器经由过程USB毗连到计算机。这个计算机图形用户界面如图8所示。      挑选BLDC机电换向极性设置许可此编码器装备适用于各类BLDC机电。所有的这些可调理设置存储到编码器芯片内部RAM,也可编程到片上非易失性PROM,许可这些设置在上电时读取利用。图8:iC-MH磁编码器计算机设置图形用户界面   除了可设置特性以外,让我们思索以下这些会有助于提高运动掌握使用的系统性能特性。 分辨率 回忆图1和图2所示的设想,假如这个编码器输出是100 CPR(每扭转正交轮回次数)大概400正交沿,将其改动到一个较高的值如1000 CPR 大概4000正交沿,分辨率增长10倍。运动控制系统的角度分辨率从0.9度每扭转提高到0.09度每扭转。有一点需求留意的是运动控制器处置带宽和呼应工夫[3]。当10倍以上的脉冲加到控制器大概嵌入式微处理器,硬件和软件设计必需包管在中止和数据处理能呼应这个增加。 在许多状况下,调理分辨率需求置换编码器器件自己,但是,没有几个可选的磁和光学编码器能够用数字方法调理分辨率而无需改动编码器IC大概源磁铁/码盘。比方,iC-LNB光学编码器IC内建一个FlexCount模块,这个模块许可改动分辨率到任何要求的CPR,从1至65,536 CPR无需改动本身的码盘。 外形尺寸   单芯片编码器供给了一个十分小的外形尺寸。小的封装尺寸许可编码器的电路板十分松散,能够在狭窄的空间利用。这就能够许可一个编码器解决方案利用到之前一个不能利用到的处所。 编码器传感器输入   编码器输入的黑白决议它的输出,一个提高机能的简朴办法是改进编码器的输入来实现。关于磁编码器IC,这个能够是挑选更高质量的某种情势的磁铁,减小磁铁到编码器芯片之间的气隙以及优化机器齐心度设想。关于光学编码器IC,这能够是挑选更高质量的某种情势的LED,一样的也要减小气隙和优化机械设计。经由过程如许做来提高编码器反应来提高控制系统机能。 精度校准   固然机器调解是一个可选办法以外,操纵单芯片编码器经由过程一个串行接口设置它的内部参数供给了一个更加准确的编码器校准计划。  如图9所示,SinCosYzer是一个数据收罗体系。经由过程输入编码器的正弦和余弦旌旗灯号,很多差别的丈量值被显现用来协助校准。李育莎曲线,偏差曲线以及以位和度暗示的精度。因为这些设置是及时显现的,可无休止的调解,只需求经由过程编码器芯片计算机图形用户界面来完成,如图8所示,经由过程内部旌旗灯号幅度调度,偏置调度以致相位调度编码器的正弦和余弦旌旗灯号的办法改动编码器的内部设置。 图9:SinCosYzer 编码器校准东西 编码器旌旗灯号位置调解   调解编码器的零位旌旗灯号供给另一种提高系统性能的办法。如图10所示,iC-MH磁编码器的索引或Z位置能够数字化的在1.4度的步长内调解。U脉冲的机电换向zero位置大概上升沿也能够在1.4度的步长内调解。这供给了一个在使用中灵敏界说原位置的办法。不像霍尔传感器感知BLDC机电磁极的位置是在一个牢固的处所,单芯片编码器能够发生这些机电换向旌旗灯号然后许可微调它们来加强驱动机电本身的机能。图10:iC-MH ABZ和BLDC UVW机电换向旌旗灯号 5)择要 和尺度封型编码器比拟,单芯片编码器IC供给了一个高度灵敏和高度可设置的编码器计划。另外,基于单芯片编码器设想,具有了经由过程一个数字接口调理编码器设置的才能。经由过程进一步加强运动掌握反应来提高全部体系的机能。 
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relative position encoder design: magnetic encoder or optical encoder
绝对值编码器设想:是选磁编码器仍是光学编码器  磁位置编码器的角度分辨率和精确度与径向的磁铁扫描霍尔传感器的中心有关,受限于可行的插补细分深度和有用的磁场质量。经由过程每扭转扫描多个正弦周期,光学位置编码器具有更高的分辨率。假如利用磁码盘,这种方法也适用于磁编码器体系,可是哪个体系更好?  本文形貌磁和光学单芯片编码器的枢纽参数,衡量两种解决方案和比力两种编码器的机能来到达挑选设计方案的目标。                   目次引见两种传感器,两种系统线性使用比力两种扭转编码器使用体系4.1)装配公役和抵偿特性4.2)能够的偏差滥觞  5.结论:哪个更好?                                           1)引见   现在的绝对位置传感器的制造需求与丈量精度以及尺寸巨细均和本钱有关,并且常常及其多样化。好的挑选是找到仅有的一个得当的体系解决方案来顺应手头的使命。所要处理的问题是耗时的,因为不仅是传感器的机器构造,并且每一个没有表现在元件规格书里的的参数也要思索出去。另外,开辟集成传感器芯片必需基于一个给定的丈量安装,大概供给适宜能够的婚配。  光学扫描器凡是利用零丁封装,便利对光电二极管阵列停止几何修正。但是,关于磁的霍尔编码器不具有可比的有用选项,为此不得不供给一个适宜的传感器阵列在芯片内部,大概接纳其他办法,由芯片规划决议磁铁的目标。小的外形尺寸和最好机能凡是是这两种解决方案都具有挑战性的设想目的。本文比力一个16管脚DFN封装的18位磁单芯片霍尔编码器iC-MU和一个optoQFN封装的18位光学编码器iC-LNB。2)两种传感器两种系统  多通道光电子扫描器iC-LNB捕捉绝对位置数据用于线性位移丈量体系大概扭转编码器(图1)。同步扫描一个10位二进制码,附加一个模仿的旌旗灯号轨道用来评价及时的插补细分,利用一个小的编码量来到达高的角度分辨率。希冀获得的绝对值位置和增量位置分辨率利用内部的"FlexCount"算法得出,供给1至65536范围内随便脉冲数目的分辨率供挑选。                                           图1.光扫描器iC-LNB  编码窗口宽度仅5.2mm,撑持利用较小的码盘大概较大直径的空心轴。伴随着节能的iC-SN85 LED来担任一个松散的光源和iC-LNB的监视器,以及掌握照度的级别。枢纽的逻辑处置也由iC-LNB内部施行,而更庞大的使命也可由一个内部的微控制器施行。  偏置和幅度抵偿功用已被集成到芯片内部,用于改正模仿轨道旌旗灯号,这些旌旗灯号也由差分的1024个周期的正弦和余弦旌旗灯号经由过程四个输出端口输出。由旌旗灯号改正电路来低落插补细分的偏差并得到更高的位置数据精度。 位置数据输出能够是并行的(高达16位)大概是串行的(利用一个快速移位寄存器)。时钟速率高达16MHz,许可轮回读出工夫小于1us。3.3V兼容的SPI端口撑持器件设置和用来扫描位置数据以及诊断动静(比方,当奇偶校验位翻开,存储监督标记一个毛病)。最大许可速度依赖于分辨率;当17位分辨率时可获得6000rpm(表1)。                    表1:元件电气参数  霍尔编码器iC-MU是一个选集成的单芯片器件,是幻想的磁码盘、磁鼓和磁带扫描器,适用于运控掌握使用。典范使用包罗绝对位置编码器、增量编码器以及用于无刷机电的换向编码器(图2)。位置数据被及时捕捉并由串行接口(BiSS,SSI以及SPI)和一个增量接口两同时输出。随便数目的分辨率脉冲数能够利用内部"FlexCount"算法再次挑选。   接纳适宜的磁丈量机构,设有两个增量轨道,极广大约1.28mm,每一个磁极对是差分的,由另一个磁极对穿插穿过丈量距离。两个同步的正弦-数字转换器用来数字化霍尔传感器旌旗灯号;这些矢量跟随转换器跟随磁场变革率达8 MSPS,无延时。   由两个轨道旌旗灯号之间的相位差,集成的掩膜-已编程旌旗灯号处理器计较绝对位置基于游标道理。利用这个道理,运动掌握不必要得到绝对位置。在扭转使用中,可获得一个19位的分辨率(相当于2.5弧度秒),当利用磁码盘 MU2S 30-32时,以及撑持的速度高达12000 rpm。   经由过程摆设磁极对在一个高分子磁铁上面的一个扁平码盘,可成立一个松散的体系,它能够幻想的间接安装到机电的法兰上。扫描事情间隔于芯片平面约莫0.4mm。   设想于一个16脚的DFN封装,iC-MU集成局部的所需编码器功用在最小能够的空间,仅5*5mm。偏疼大概偏轴安排撑持空心轴用于高分辨率的磁绝对值编码器。合适的磁码盘直径为30mm,撑持空心轴直径高达10mm。                                  图2:磁传感器芯片和磁码盘   经由过程设置细分因数从1到65536,数字角度位置能够从ABZ接口以任何分辨率输出。因为内部的"FlexCount"算法,全部范畴的分辨率参数仅利用一只传感器就能够满意。这许可一个设想合适各类编码器分辨率而无需改动丈量安装。完整安装好编码器的位置当前也能够编程,以起码的工夫托付上市。并且,zero位置旌旗灯号也能够在装配好当前再编程。   iC-MU能够发生3个换向旌旗灯号(U、V和W)来运转无刷直流电机,合适机电极对从1到16。因为准确的电子调理UVW旌旗灯号能够根据转子的位置改动而供给了一个枢纽的优势,使得不再需求凡是利用的霍尔开关体系。   因为能够撑持空心轴使用,能够利用一个兼容的装配交换扭转变压器。作为全部体系的一部分,这将招致一个更自制的扭转变压器交换解决方案发生,跟着它的高分辨率,撑持更准确的机电掌握。   SPI接口能够直接连接到一个微控制器,BiSS用于双向通信和CRC校验的超长间隔通讯,以及SSI是一个尺度的编码器接口。所有的接口许可时钟频次高达10MHz。   关于数据输入,iC-MU在BiSS和谈下撑持多从机使用链式毗连,利用同步时钟毗连多个编码器来捕捉数据。假如一个相干编码器已毗连并设置和开端事情,绝对精度有可能在最高速度时记载、评价以及由一个微控制器校订,这个微控制器可许可在体系中担任一个交互的输出接口。3)线性使用  iC-MU撑持40,80,大概160mm间隔的绝对线性丈量,位置分辨率约莫160nm。两个器件可被级联用于更大的间隔,使得最大能够的丈量绝对间隔耽误,由2到64的一个因数肯定(图3)。这使得绝对间隔丈量体系能够到达数米,丈量速度高达16m/s。                      图3:元件级联用于线性丈量体系和大空心轴使用   比方,决议图3的多圈设想绝对位置丈量来自于中央轨道的1024个轮回和上面轨道的1023个轮回。相位差由高出全部2.6米的丈量长度决议。上面的这颗iC-MU(1)在中央轨道的1024个轮回和上面轨道的992个轮回之间计较相位差。此安装因而反复发生32次位置数据,高出全部丈量长度。 多圈数据来自于iC-MU(2),用来辨别这32个段。   另外,级联两个iC-MU霍尔编码器,其他多圈传感器(齿轮箱)也能够用来供给它的多圈数据给iC-MU。一旦供应电源,多圈数据主动读取,而且在计量模式时期周期性查抄。4)比力两种扭转编码器使用体系   两种编码器的传感器构造曾经肯定,撑持小尺寸和本钱敏感的产物而没有捐躯任何丈量精度(图4)。虽然这两种器件接纳差别的电路设计办法,它们同享相似的机能特性(表1);撑持随便可编程脉冲数的及时高绝对值和增量旌旗灯号分辨率。 图4:装配道理和尺寸比力  当挑选根本的体系规划时其他决议身分也必需思索出来,比方应用领域和丈量精度要求。表2比力了次要的传感器规格参数。 表2:光和磁传感器的特性比力  跟着完善的电子处置丈量体系,磁码盘的磁极间距偏差是绝对测量误差的闪现滥觞。比方,一个典范的磁精度是15um,而光学码盘的线精度是300nm,不同是不言而喻的。借助于扫描半径(表3),这个值能够被转换成角度偏差;在理论上,磁编码器体系约莫为0.07°(252弧度秒)以及光编码器体系约莫为0.0018°(6.4弧度秒)。光学系统其它的次要偏差滥觞总计为0.011°(40弧度秒)。   用户挑选一个特定的体系主要依据这个体系的长处和缺陷。比方,磁编码器体系具有多种优势的情况免疫力,诸如,尘埃、油污以及水汽。它也许可一个宽的事情间隔,许可轴向间隙和安装公役较大而简单装配。因为磁编码器体系无需LED和光学器件,一个扁平的编码器设想成为能够,   关于芯片设计者,当开辟电路时传感器的旌旗灯号饰演着一个次要的脚色。光学传感器读取轴角由光学码盘发生的光散布和强度决议。好的旌旗灯号对比度必需制止成像毛病。为了打败这个,特别的编码器LED供给平均性的平行光,iC-SN85是一个适宜的LED。它撑持约莫200nA的光电流发生,在传输阻抗为1MΩ时发生的旌旗灯号电压为200mV。   关于磁传感器,磁场重量垂直于芯片是无益的。霍尔效应间接供给一个典范的mV级电压,依赖于磁场强度重量Z。因为单个霍尔元件仅能感知到磁铁的间隔,而接纳多个霍尔元件在差别位置记载磁场的Z重量以便角度信息可由各个部分的磁场突变得出评价。霍尔元件必需真实地“感知”这个蜿蜒的近场磁力线。因为霍尔电压的极性跟从磁场的标的目的,磁铁的北极可区分于南极,使得利用一个极对来肯定绝对角度成为能够。   霍尔元件最多仅能从磁码盘的磁场发生10mV的电压。为了到达光学编码器体系的分辨率,旌旗灯号的带宽必需被限定。为了到达旌旗灯号调度的目标,霍尔元件利用一个牢固的扫描频次和滤波来评价。这个霍尔传感器饰演了一个模仿低通脚色,截止频率约莫20kHz。但是,实际上,较长的旌旗灯号传输延时是不相关的。 4.1)装配公役和抵偿特性  两个体系都利用快速及时插补细分电路由向量追踪转换器利用arc tangent停止转换。关于偏置、幅度婚配、相位精度和谐波,此转换器依赖于模仿的正弦/余弦传感器旌旗灯号。但是,与幻想的装配位置的偏向惹起的旌旗灯号偏差会减小插补细分的精度。为了确保丈量精度,两个体系都许可静态校准由装配惹起的旌旗灯号偏差和经由过程集成的D/A转换器校订调理几个模仿旌旗灯号途径。   电子旌旗灯号校准会增大机器活动限定度(表3)。iC-MU也许可正弦/余弦相移校准,这也能抵偿径向瞄准偏差。一旦设置和校准,所挑选的事情点由主动功用来保持。关于光学编码器,集成的LED功率掌握抵偿由温度上升惹起的LED服从丧失。霍尔编码器有一个增益掌握用来抵偿当磁码盘与芯片间隔的变革时惹起的场强改动。 表3:机器数据和装配公役 4.2)能够的偏差滥觞  原则上,偏差该当被全盘思索出来。在这里,已对基本情况停止了考查,拿霍尔编码器作为一个例子。假如丈量用磁铁的相干几何尺寸已被思索出来,这些考查成果也一样合用于光学编码器体系。   假如霍尔编码器在扫描半径对齐不幻想,将会惹起正弦旌旗灯号失真。假如有一个半径位移(ΔR),霍尔元件不能探测到磁体大概探测到分段的磁极不在准确的位置(图5B)。正弦和余弦旌旗灯号就会有一个牢固的位移偏差在随后的扫描中呈现。但是,这也能够经由过程利用集成的旌旗灯号校订电路获得抵偿。表达式1:因为径向瞄准惹起的测量误差   表达式1给出了传感器旌旗灯号电子相位偏差,D为扫描直径,ΔR为扫描位移。比方,参考电子正弦周期旌旗灯号,一个霍尔编码器径向0.1mm位移会发生0.35°的相移在扫描直径为26mmm时。假如计较每扭转的机器角度偏差,成果必需除以极对数。一个尺度磁码盘有32个极对,相当于机器角度偏差为0.01°。  另一方面,器件在切线标的目的的位移(ΔX)对两个轨道旌旗灯号电子角度相移的影响或大或小是不异的(图5A)。这个间距改动和相位差别仅细微地影响计较绝对位置值,实际上险些不会改动。但是,偏疼装配偏差(ΔE)会惹起装备颤动(图5C)。直径越小,丈量目的的改动越大。一个长波偏差呈现会减小绝对丈量精度。                                             表达式2:由偏疼率惹起的测量误差 偏疼率偏差来自于丈量器件的位移ΔE,这个偏差来自于旋转轴和丈量磁铁的极宽p。因而,一个偏疼率10um的偏差招致相位偏差为1.4°(参考正弦周期),大概角度偏差0.05°(参考机器扭转),有关尺寸巨细,见表3,扫描直径26mm,极宽1.28mm,32极对。关于起决定性感化的相位差游标计较,偏疼率偏差饰演着一个较小的影响,因为两个旌旗灯号轨道的偏疼率是不异的。在一个完好的机器扭转360°,角度精确度优于+/-0.1°.这个精度受磁化体系的限定。假如个体的磁极变革,细微的位移影响在约莫45°和90°,如图6所示。毗连参考编码器的机器轴也发生一个轴心偏差,它能够经由过程在同一个标的目的扭转的一个长波偏离观察到。                                                                                               图6:iC-MU磁体系角度精度图6展现了iC-MU磁体系的角度丈量精度,利用磁码盘 MU2S 30-32,周期角度为11.25°。在这里,数学和图形功用在BiSS读出软件里能简单的比力丈量数据。 5)结论:哪个更好?  磁传感器手艺有许多长处可说:优良的可靠性、对打击和振动的高抵抗性、不易碎、对尘埃和水蒸气不敏感。单芯片霍尔编码器iC-MU许可利用空心轴以及可实现仅有光编码器才气做到的位置分辨率。但是,关于高丈量精度的使用,光学传感器,诸如iC-LNB等有优势,可是需求更高贵的装配本钱。可是,考虑到它们具有小的optoQFN和optoBGA封装,单芯片编码器是一个可行的挑选。基于这些枢纽点,决议挑选哪一个计划该当由使用自己的需求来决议。 
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Using smart drivers to save energy for long transmission lines
接纳智能驱动器为长距离传输线路节能  当在长距离的线路传输旌旗灯号时功率耗损会倍增,接纳智能驱动器能够使得电线大概电缆削减功率耗损。关于控制工程中旌旗灯号高电平利用24V这类特别状况,这是接纳线驱动器的一个潜伏节能优势。功率耗损降落使得线驱动器的外壳温度明显地减小。线驱动器是被设想用来转换逻辑电安然平静经过连接线传输他们作为电子输出旌旗灯号。凡是在产业控制工程利用的旌旗灯号摆率约莫24V。电缆凡是毗连到接收器,接收器接纳高阻抗来连结静态功率低消耗。关于电缆的特性阻抗,大要100 ohm,掌握单位的输入阻抗大要几千个ohm。这里所研讨的是电气上的电缆,即没有毗连的开路终端电线。  在发射端,线驱动的输出阻抗凡是调理到婚配电缆的阻抗。图1展现了一个这类驱动器的例子。这类推挽输出驱动器的输出特性能够简朴的由两个幻想的开关和一个串连的电阻Rs来等效。这两个开关HS(高边)和LS(低边)根据供应的输入电压(没有在这里画出)掌握,由掌握旌旗灯号ENHi和ENLo来发生。图1:线驱动器输出级电路原理图   最后,一个不带电的电线由切换到高边开关HS来充电,供电电压VB沿着电线经由过程串连电阻Rs和电线的特性阻抗ZL来分派。因为Rs约莫即是特性阻抗,在电线的开端端A点上电时的电势约莫为供电电压的一半(图2)。再往前(2),全部电缆由线路的颠簸停顿被充电到VB/2。  一旦线路波抵达接收器B(3),它在开路终端被反射。此反射波被叠加到输入波,招致在B点由叠加波部门设置一个即是VB的电势。接收器因而检测到一个相当于全电源电压VB的电压摆率。 全部电缆终极的电势由反射波充电到VB(4),意味着一旦反射波抵达驱动器输出端A,电势VB/2也上升到VB(5)。 驱动器输出端更进一步的反射由阻抗适配器和Rs有用的抑止,因而,线路电势会趋于一个不变值。当低边开关LS切换时,电缆以一样的方法又开端放电。图2:旌旗灯号在一个开路电线上传播 图3所示是根据开关形态从电缆的肇端端A到起点B的电压模子。另外,由驱动器自己的供电电压和接收器输入阻抗惹起的静态功率耗损是微乎其微的,相称大的线驱动器功率耗损(P)工夫在电缆的充电和放电。更长的电缆和更长的再充电工夫以及更高的再充电频次耗损的功率就越大。功率耗损跟着频次线性增长。实际上,最大利用频次由驱动器的最大功率耗损限值。图3:iC-DL在高边和低边开关有用旌旗灯号ENHi和ENLo鼓励下电缆肇端端A到终端B电压模子和驱动器功率耗损削减静态功率耗损  一种能够的由iC-HX减小静态功率耗损的办法如图4。此驱动器管脚兼容iC-DL,具有一个内部毗连一个负载电容Cx。事情时这个电容被充电到供电电压的一半(VB/2)。 图4:线驱动器带开关X和电容Cx的电路道理   iC-HX的事情出格之处是什么?旌旗灯号传输时经由过程对电缆的充电、放电和iC-DL是一样的,电源和切换实体差别,接下出处图5阐明。iC-HX在充电(1)时期高边开关HS起首由电容Cx的开关毗连到电缆代替,这将会充到电源电压的一半。因为在这种情况下电流是由无功功率供给的,这几乎没有耗损任何电源功率,除了经由过程开关X的电阻性消耗。为了反射波能被驱动器内部吸取,在反射波抵达驱动器输出端A(5)之前,电容Cx必需立刻和电缆断开而且高边开关HS有用闭合以便输出阻抗Rs变为有用。仅仅在这个长久的切换到高边开关事情和反射波抵达的霎时功率耗损和iC-DL是一样的。图5:iC-HX高边,低边和X开关在线路出发点A到起点B的有用电压旌旗灯号模子,驱动器功率耗损仅呈现在从X到HS以及X到LS长久的切换工夫   相似的情况,当电缆第一次放电时电容Cx又经由过程开关X毗连回电缆。这会惹起电缆里的能量传输返回到Cx;仅在切换到低边开关时期驱动器耗损少量能量。  潜伏的节能在于驱动器上电和断电的运转工夫的使用率有关。  因而,有用使用上述道理,再充电点安排尽量准确到仅仅在反射波返回前一点是须要的。刚开始iC-HX不知道电缆的运转工夫;它必需起首检测反射波朝向。在这个长久的“进修时期”,iC-HX根据老例事情几个轮回,和一个一般线驱动器一样,不利用Cx切换到电容。一旦电缆运转工夫契合划定,此器件主动切换到X开关模式。 潜伏节能例子  一个潜伏节能的例子由图6给出。此图所形貌的是利用四个通道,100m长电缆时驱动器的功率耗损。这是一个典范的增量编码器使用,差分旌旗灯号A和B利用差分旌旗灯号传输到掌握单位。图6:iC-DL和iC-HX利用两对100m电缆事情时功率耗损比照   如上文所述,因为电缆再充电是间歇的,跟着所传输脉冲的频次增长功率耗损也会上升。关于一个给定的频次,iC-HX节流功率耗损大要在30%到40%的范畴。相反的,这意味着在使用中由iC-HX交换iC-DL后驱动器温度上升较低。比方,用这种方法,增量编码器由间隔决议功率耗损的较高工作温度能够相称地低落到从80℃上升到100℃,在利用不异的机器装配和不异的热阻状况下,热耗散较低。 
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澳门新普京
Flexible Sensor Signal Conditioning and Safe Transmission`
灵敏的传感器旌旗灯号调度和安全传输单芯片传感器旌旗灯号调度器集成附加功用供给灵敏的旌旗灯号调度专业的传感器记载林林总总物理参数提供给人大概机械用来更好的决议计划和优化处置。为了到达希冀的成果,传感器的旌旗灯号质量和功用安全是一样主要的。另外,转换这些被丈量的参数须要时该当尽量的准确和包罗易于集成的电子输出级。设计者面临的一个应战是便宜的放大这些小旌旗灯号,这些旌旗灯号凡是具有非线性以及参数受温度影响。利用上面的这些办法来调度它们,使得在卑劣的产业情况下经由过程长电缆可以包管安全传输。 设计者也需求决议假如要传输旌旗灯号,传输的旌旗灯号是数字的仍是模仿的。本文概述了针对这个问题的能够办法,形貌了一个通用的构造、集成的、可编程的旌旗灯号调度器用于线性和扭转编码器、AMR传感器和光学传感器的旌旗灯号预处理,来满意产业使用的要求。旌旗灯号的质量和毛病庇护是决定性的为到达最好的顺应和评价各类传感器元件,比方,用来丈量温度、压力/压强、加速度、位置或光强度,需求一个仪表放大器来供给一个须要的放大。仪表放大器是一个差分器件,两个输入一样放大;它要求必需包罗灵敏的、可调理的和具有一个高阻抗输入来处置这些十分微小的传感器旌旗灯号。它也必需具有抵偿才能来抵偿因为消费惹起的制造偏向。在旌旗灯号调度级,该当考虑到由温度或温度漂移以及保守、抑止惹起的非线性影响,还要制止噪声或在传感器感到的滋扰。传感器桥阵列(典范的是惠斯通电桥)特别合适抑止共模滋扰以及即便细微的电压改动也可以供给一个充足的旌旗灯号质量。当需求在旌旗灯号通道定位能够的旌旗灯号毛病源时,思索上面的这些可能性: 1、查抄线路断路大概短路 2、在传感器上大概在旌旗灯号传输时期感到的滋扰 3、电源供电中止大概接地不良 4、超越最大工作温度范畴一个个冗余的旌旗灯号途径模式已被证实在高要求的毛病庇护状况下是明智的,但传感器旌旗灯号电缆的本钱将会更加。一个好的折衷是以传感器旌旗灯号的差别作为条件来简朴的检测信号线毛病,以及分离这个利用一个集成的温度探测器和一个电压探测器和传感器监控功用来供给各类诊断功用,包罗辨认传感器焊接和线缆生效以及温度监控。关于传输传感器旌旗灯号,一个供替换的挑选是在旌旗灯号调度以后立刻数字化这些值,然后利用安全的数字和谈传输它们。为了到达较高的丈量分辨率,每一个传感器需求一个ADC,而这将涉及到更高的利用庞大的现场总线和谈的本钱。 简朴的电压旌旗灯号(比方,0-10V)大概电流旌旗灯号(比方,4-20mA)接口是相称通用的但不供给尺度监控。体系设计者因而挑选差分传输模仿丈量值,差分传输使得传感器旌旗灯号在驱动器方面逻辑是有用的以及即便利用长的毗连电缆共模滋扰也会获得抑止。接纳这些倡议,iC-Haus构想了iC-TW3,一个差分的,三通道可编程旌旗灯号调度器,装备100-120Ω闭环差分线驱动器。 一个通用的旌旗灯号调度器图1所示的是iC-TW3通用旌旗灯号调度器的差分旌旗灯号通路。此器件由一个可编程输入放大器、一个偏置抵偿级、一个动态滤波器和一个差分输出放大器构成。输入偏置、增益和低通滤波器频次可在此旌旗灯号通路中设置。在所有三级放大笼盖的-6到57dB范畴可由距离0.08dB停止设置。一个统共±1240mV的偏置电压可由多个40mV设置给前端放大器。一个统共±2.54mV的偏置抵偿值能够2mV为单元由下流的动态滤波器放大器设置。输出放大器也包罗差分线驱动器和鞭策已调解的旌旗灯号,以便利用一个低阻线终端(比方,120Ω)也能够用来间接传输1Vpp的旌旗灯号。图1:传感器旌旗灯号调度通路此放大器输入也能够事情在单端模式。假如有如许的需求,则放大器负的输入端要毗连到VDD/2。作为一个附加的挑选,毗连到传感器器件的线缆断开能够由切换到内部的2MΩ上拉电阻来监控。发作此毛病变乱,旌旗灯号调度器iC-TW3由NERR输出一个低电平标记发生了一个传感器断开变乱。 主动温度抵偿  温度毛病凡是在传感器部门没有抵偿,但会在中心计算机、微控制器、PLC大概驱动器抵偿。温度间接由传感器丈量而且作为一附加参数被传输。作为一种挑选,温度能够在传感器部门丈量,用来限定监控和施行当地抵偿。前面的这种方法基于两个温度丈量点的线性插补细分。为此,iC-TW3许可一个总计16个自由选择的插补细分点在0-255的范畴,包罗最低值0和最高值255。利用集成的温度传感器,这相当于-50℃到150℃的范畴。但是,两点间隔之间的温度传感器曲线能够自在地挑选以及能够被调理到合适任何范例的曲线。这些插补细分点存储在一个查找内外,iC-TW3主动地差补细分通道A和通道B的增益和偏置与通道Z的偏置一样好。一个总计五个8位的值给能够的16个插补细分点,存储在I2C毗连的EEPROM表格里。这个例子如图2所示,七个界说好的差补细分点用于温度抵偿来改正所毗连的传感器的偏置和增益的非线性。图2:插补细分温度抵偿增益和偏置一个内部温度传感器也能够被毗连到iC-TW3,此传感器该当从物理上离隔电子和其他环境温度的影响。一个在-50℃和150℃之间的8位的值被用来界说一个可选择的门限温度触发警报。这个警报由iC-TW3的ERR管脚输出一个低电平,此也能够被用来驱动一个通用毛病LED唆使。 由微控制器大概一台计算机来调度  iC-TW3由一个双向的脉宽调制1-线接口来读/写会见所有的寄存器,好像毗连的参数存储器件(一个尺度的I2C EEPROM)。在实践使用中能够经由过程一个微控制器的端口间接掌握。此毗连也能够设置成一个光学的只-写毗连,假如是密封的传感器抵偿,需求“无线”设置。比方,经由过程一个光传输窗口完成。可供给一个适配器用来开辟和设想利用,它能够毗连到一般计算机大概笔记本电脑的USB接口。图3形貌了iC-TW3的图形用户界面用于调度旌旗灯号通路A和B。在开辟时期,这许可用户肯定所有的前置放大器的增益和偏置、滤波器和输出放大器的参数。事情模式设置(差分大概单端)和传感器毛病监控也能够利用这个东西来编程设置。假如设置被挑选,所有新的设置经由过程软件立刻写入iC-TW3毗连的EEPROM。当前iC-TW3的丈量温度、EEPROM校验和报警、超平和传感器毛病也形象的显现出来。每一个旌旗灯号增益途径能够设置为省电模式来节流功耗。 第三个通道Z旌旗灯号通路的设置是类似的。这能够用来扫描增量编码器的参考轨道,用于角度和运动丈量大概作为一个可调理的比力器撑持增益和偏置正告设置。主动偏置抵偿周期旌旗灯号,比方那些正弦/余弦扫描和最大顺应频次以及目的幅度(内部1/2VPP或一个预设的内部值),利用Misc菜单挑选所有的传感器旌旗灯号通道。这也能够用来切换温度抵偿的开关和设置最高温度限定。插补细分点和温度抵偿特性曲线特性(多达16个查找表)经由过程一个集成编辑器编纂(经由过程菜单Extras会见)。图3:经由过程USB接口调度旌旗灯号用于开辟和消费传感器桥使用  图4是一个运动传感器电路图,经由过程磁大概光传感器桥扫描两个差分轨道,然后调度这些周期的正弦/余弦旌旗灯号,放大到1Vpp以及经由过程毗连电缆差分传输他们给一个120Ω的线路终端。视状况,一个索引传感器旌旗灯号能够经iC-TW3的第三个通道调解处置和传输。这种方法的优越性是差分的正弦/余弦传输实际上不受接口影响,以至于它的逻辑可考证性,确保使用电路的功用安全。在接收器部门调度过的传感器旌旗灯号也能够利用一个十分高的分辨率数字化,使得线缆短路和断路在接收器部门能简单的被辨认。图4:运动传感器带正弦/余弦旌旗灯号调度和差分模仿传输上电后,iC-TW3从EEPROM提取事情模式和校准数据添补到它的内部RAM。照旧能够经由过程1-线接口会见它,许可从头抵偿大概改动事情模式。然后,这些变动可由iC-TW3写入EEPROM。假如iC-TW3检测到一个毛病(比方超温、EEPROM校验毛病大概传感器器件连接线断开),NERR输出被激活。这个报警然后可由一个数字输出驱动器经由过程长的线路大概电缆传输。 内置安全功能  而图4所示的体系撑持安全的差分线在120Ω的负载线驱动,图5所示的体系撑持100Ω线驱动。图5所示的是磁增量编码器的例子,磁传感器桥大概光旌旗灯号被iC-MSB用iC-TW3类似的办法放大和调度。在线缆带100Ω的终端电阻,iC-SMB供给一个摆率为1Vpp值而且撑持短路庇护和容错。iC-SMB电路经由过程了生效模式与影响阐发(FMEA),因而合适在安全使用中利用,比方西门子数控产物体系。图5:磁编码器带模仿旌旗灯号传输适用于关键性安全使用由上所述,传感器旌旗灯号调度该当包罗灵敏的旌旗灯号调度设置、局部的旌旗灯号传输途径、包罗旌旗灯号调度和模仿线驱动器。这些会协助减小体系本钱和满意功用安全需求。片上温度传感和主动偏置抵偿供给了新的办法去提高系统性能和削减控制系统的工作量。 )
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接纳集成电路激光二极管驱动器提高产物机能削减消费及保护本钱
接纳集成电路激光二极管驱动器提高产物机能削减消费及保护本钱设想应战在设想低功耗激光二极管驱动电路时,设计者能够挑选利用经典的分立元件解决方案大概利用初级的全集成电路解决方案。凡是设计者在挑选计划时只考虑到元器件的本钱身分,没有考虑到全部体系本钱设想。消费,测试以及售后撑持要在在全部产物期限时期,次要的关键因素思索以下:在全部供电电压范畴和工作温度范围内输出功率的稳定性;可靠性;空间要求和激光二极管庇护;装配,测试,以及调校本钱;电路设计和测试工夫;元件采购和运输成本;潜伏的售后包管本钱;凡是被疏忽的大多状况是激光模块中价格最大的部门,即激光二极管自己。因而,庇护好激光二极管是一个有益的投资,虽然这个电路需求较高的元件本钱。分立元件驱动电路如图1所示,是一个典范的分立元件APC(主动功率掌握)驱动解决方案,用于供电电压范畴从6到12V的持续颠簸模式。在这种情况下通用运算放大器加1只齐纳二极管,1只三极管和17只无源元件用来掌握输出功率。电路大要需求6cm2板子空间,没有激光二极管反极性庇护和毛病庇护。这个分立元件解决方案电路启动工夫大概是20毫秒。图1:典范的分立元件激光二极管驱动电路 集成电路驱动器     图2所示的激光管驱动解决方案是利用集成电路iC-WKN,一个公用的APC激光二极管驱动器IC用于持续波事情,事情电压从2.4V到15V,高达300毫安驱动电流。此计划仅需4个附加无源元件来构建一个完好的驱动器。全部电路板占用空间约莫1.25cm2,占用空间比分立元件计划缩小了4倍。此电路IC内建接反极性庇护,过流和超温断电。上电软启动(典范值70us)。此电路也庇护激光二极管免瞬态打击和在宽电压范畴供电时连结输出功率不变。图2:集成电路激光二极管管驱动器结论图3所示的图表是在6至12V供电时分别丈量的两个计划的激光二极管输出功率稳定性。分立元件解决方案输出功率在供电电压范围内偏向大要10%,集成电路iC-WKN解决方案输出功率在不异供电电压范围内偏向小于1.5%。 图3:分立元件和集成电路解决方案功率输出变革范畴 在可靠性方面必需思索分立元件解决方案有46个焊接点,集成电路IC-WKN解决方案仅有17个焊接点。分立元件解决方案多于两倍数目的焊接点和超越4倍数量的元件是间接影响MTBF(均匀毛病间隔时间)的身分(MIL-HDBK-217尺度)。当比力分立元件解决方案和集成电路解决方案的总成本时不得不思索以下6个方面的主要部门:部件;装配;调理和测试;部件采购本钱;库存本钱;潜伏的售后包管本钱;仅思索部件本钱需求,集成电路解决方案本钱约莫贵两倍多于分立元件解决方案。可是较大数目元件的分立元件解决方案增长了装配本钱,一样增长了两个电位器的手工调理输出功率本钱。在这种情况下分立元件解决方案的装配,调理和测试本钱约莫贵两倍多于集成电路解决方案。因而两个解决方案的本钱相互相称。集成电路解决方案全部体系的可靠性,稳定性和庇护激光二极管较着更好。 必需考虑到分立元件解决方案因为元件部件数目多,焊点多,交换或维修的本钱。 表格1概述了两个解决方案的比力成果。 参数比力分立元件解决方案(图1)集成电路解决方案(图2)输出功率稳定性(供电电压6-12V)约莫10%小于1.5%元件数目20只5只板子空间约莫6平方厘米约莫1.25平方厘米相干本钱部件装配调理和测试 122 211接反极性庇护无有瞬态庇护无有过流封闭无有超温封闭无有启动工夫约莫20ms约莫70us均匀毛病间隔时间12.2  表格1:分立元件和集成电路解决方案比力  
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Fast and simple measurement of position changes
简朴快速的丈量位置变革  加工机器位置体系、精细丈量仪器以及搬运机器人需求快速的记载位置数据,也需求快速的辨认出任何变革。高分辨率编码器和光栅尺经由过程一个编码器接口反应位置数据给控制中心。挑选的这个接口必需满意掌握单位对工夫的要求。关于设计者,具有太多的编码器接口可供挑选,如许就使得挑选编码器接口的使命和完成这个使命一样的庞大。除了那些浩瀚的专有数字接口,也有一些开放的尺度接口,比方,SSI和BiSS接口用于绝度位置读取。但是,假如方向上的或一个十分高的位置分辨率变革需求一个快速的捕捉,串行数据接口的吞吐才能是有限的。作为另一个挑选,有许多传统的开放编码器接口可供传输位置数据,比方利用正弦/余弦旌旗灯号大概增量A/B旌旗灯号传输位置数据都很好。上面的文章形貌这方面的需求、替换挑选以及可行的解决方案。                                           目次1.挑选编码器接口2.利用当前值快速掌握3.仅仅计数是不敷的!4.构建一个快速编码器接口5.择要 挑选编码器接口在利用控制器大概PLC的线性/扭转编码器的体系中挪用一个接口模块(如图1)。许多控制器厂商供给必然范畴的专有大概开源接口。 模仿接口模仿接口是传统的非专有接口,传输位置信息利用模仿旌旗灯号。在领受方,既能够利用正弦/余弦值供插补细分器细分,也能够利用电流大概电压旌旗灯号(比方,0-20mA 或 0-10V)肯定绝对位置。后者长短常通用的接口,用于简朴的位置编码器。在安全应用领域,模仿差分正弦/余弦旌旗灯号收发器是优先挑选的,差分旌旗灯号的毛病第一时间能够被检测到,因而合适这类使用。图1:控制器或PLC的编码器接口 数字绝对值接口最快的传输数字绝对位置数据的办法是经由过程一个并行接口。这个接口凡是由TTL驱动器担任。但是,并行接口线缆的本钱十分高,由于这个缘故原由这种方法不是出格受欢迎。其他办法愈来愈盛行了,包罗利用尺度的非专有现场总线用于串行传输,比方,CANopen、以太网以及开源的SSI/BiSS接口。 数字增量接口另一个传统串行编码器接口利用两个相移90°的A和B旌旗灯号供给增量传输位置变革数据,就是尽人皆知的正交旌旗灯号。另外,一个Z脉冲旌旗灯号供给零位旌旗灯号用于零位探测。关于增量接口,一个方向上的改动由A到B旌旗灯号的相移大概B到A旌旗灯号的相移变革暗示。图2所示的是一个接近zero位置的标的目的改动时序图。这里给出的是一个扭转运动标的目的改动时的分辨率,是一个角度,滞后1.4°。如图所示,A,B增量旌旗灯号相移许可探测标的目的用于向下和向上的计数。在这个例子里,一个轮回内,A/B旌旗灯号供给360°的边缘(H至L大概L至H)。标的目的鉴别器必需评价这些边缘的相位差以及激活向上/向下计数器。这例子是编码器其时的绝对位置信息。图2:增量编码器接口和A,B,Z旌旗灯号时序图   增量编码器接口的优越性在于低成本和对线缆的低要求。典范的设置包罗TTL驱动器输出、集电极开路输出以及线驱动器输出。TTL驱动器和集电极开路器是更低成本的解决方案,线驱动器供给很多良好的机能。这些初级机能包罗差分驱动器的抗干扰性、可驱动长距离线缆运转、高效的功率耗损以及快速串行传输机能的提高。差分对传输器得益于利用公用的RS422驱动器,供给更好的适应性。标的目的的改动也能够被快速的探测,速度由简朴的丈量两个Z零位脉冲之间的沿间隔来肯定。但是,一个绝对位置仅在一个Z零位脉冲抵达以后有用。关于扭转运动,绝对位置在最少一个轮回以后得到。为此,线性丈量体系需求一个参考大概肇端序列优先于通例运转。 利用当前值快速掌握高精度使用和高速运动发生十分高的时钟频次,这不得不由接口模块来处置。思索这类高速度和位置掌握,可实现的掌握轮回依赖于固件的算法和硬件的延时工夫。举例说明,图3图解了一个机电控制系统的构成。除了固件的执行时间以外,以下的硬件执行时间也要出格留意思索出来:1.    编码器延时:插补细分器的处置工夫和A/B旌旗灯号的输出耗时。2.    编码器和掌握单位/PLC之间的传输工夫。3.    掌握单位/PLC的编码器接口模块读出工夫图3:一个机电掌握回路的按时组成部分编码器提早    编码器提早(TLZ)依赖于模仿放大器的带宽,其内部的插补细分处置、分辨率以及其利用的编码器接口。 插补细分器提早假如模仿编码器旌旗灯号正弦/余弦插补细分是一个基于MCU/DSP体系,提早周期能够超越200us或更多。出格要留意的是当利用较高频次和分辨率,尤其是协同多轴掌握和冗余体系。在这种情况下,提早能够招致位置数据大概不是当前的大概不同步。为驱逐这个应战,一个基于超快闪速(flash)插补细分器能够担任此使命(比方,iC-NV)。iC-NV是并行内部处置,可获得延时少于1us的插补细分器。 编码器接口提早当接纳串行编码器接口时,凡是只饰演偏重要脚色的是数据传输工夫。关于串行传输,MCU/DSP从编码器接口模块的位置数据读出工夫Tread,取决于数据位宽和团体速度。比方,SSI在10MHz运转,32位宽,传输工夫为3.2us。关于增量接口,提早凡是能够疏忽,给出及时性位置运动编码器旌旗灯号边缘。但是,标的目的的改动将增长一些数目的提早,取决于增量旌旗灯号的迟滞(见图2)。 处置提早一旦位置数据通过编码器接口被读取,软件算法处置工夫(TS/W)增长了体系提早。这将在差别体系之间因为体系自己的处置工夫而大为差别,取决于利用的MCU大概DSP的构架和处置才能。 机电提早在位置数据被读取和处置以后,终极的提早属于机电驱动器本身的一部分。激活机电(Tdriver)和随后的反应时间(Tmotor)必需被加到全部的体系提早。所有的这些延时工夫加到体系提早,这个提早会间接影响全部掌握周期的持续时间。反过来,这也影响生产率和全部机械机电控制系统的精度。 3)仅计数是不敷的!机电的速度和编码器的分辨率肯定被处置的脉冲的反复率。但是,当挑选一个编码器的时分必需一并思索其他身分。 编码器挑选例子以一个高速使用为例,磁编码器体系,比方iC-MH在分辨率为10位时许可机电速度高达480,000 RPM。这些器件也一样供给相干的机电换向旌旗灯号UVW。典范的机电速度凡是在500到15,000RMP范畴之内。但是,凡是要求的分辨率为12位大概以上。在这种情况下,一个速度为120,000RPM和12位位置分辨率的编码器能够由iC-MH完成。iC-MH是一个单芯片绝对值编码器器件,供给多种编码器接口。包罗两个串行SSI/BiSS传输接口和一个增量接口。聚焦这个尺度增量旌旗灯号,A/B旌旗灯号的沿反复率达8MHz。这许可一个大于125ns的最小沿间隔间隔在两个A/B旌旗灯号沿之间(见图4a:多种电子插补细分器/编码器特性)。图4a::多种电子插补细分器/编码器特性 位宽和速度图4b给出了每扭转编码器的脉冲数,取决于速度。在一个15位分辨率以及10,000RPM反复率时险些到达5.5MHz。尺度编码器仅在低速时能得到像如许的分辨率。跟着标的目的改动,最小沿间隔非常重要并且必需被思索出来。图4b:脉冲速率取决于速度和分辨率直线机电例子假如利用直线机电,凡是需求的速度为几米每秒。关于无芯直线机电,以至可以获得超越7m/s的速度。关于光栅尺或磁栅尺,其供给一个周期距离20um的正弦/余弦旌旗灯号。若由接纳一个分辨率因数为16的插补细分器细分,比方,接纳iC-NQC,可到达1.3us的分辨率。在直线速度为2m/s时,脉冲反复率为1.6MHz。除了脉冲反复率和A/B旌旗灯号的最小沿距离以外,在开辟时期也要服从上面的这几方面: 多轴位置在tX时辰同步存储简朴的速度丈量在A/B旌旗灯号传输时期检测平衡/偏差可编程计数器的长度要考虑到差别的丈量精度单端和差分两种办法评价A,B和Z旌旗灯号 4)构建一个快速增量接口增量编码器能够用多种差别的办法毗连,关于十分迟缓的运动,利用MCU的固件和一个中止来评价旌旗灯号沿便可。假如利用一个内部标的目的鉴别器,大概利用一个集成到MCU内部的标的目的鉴别器,数KHz频次的A/B旌旗灯号或许由MCU的内部定时器/计数器能胜任此扫描使命。关于产业控制器/机电控制系统,FPGA也常常用来构建编码器的接口。取决于此处理器的构架,有些这方面的一些体系有范围以及不能处置高频次的编码器。但是,接纳新开辟的嵌入式控制器和公用的编码器处理器能够协助设计者处理此范例的设想应战。iC-MD是一个此范例的编码器处置器件,如图5所示,此器件供给一个完整的增量编码器接口和集成的差分RS422线接收器。iC-MD也能够毗连到一个SPI接口大概一个SSI/BiSS接口。iC-MD集成的标的目的鉴别器激活可编程长度的同步向上/向下计数器。此许可高达3个通道,每一个通道可设置高达16位,大概设置为两个24位计数器,大概设置为一个32位计数器,大概设置为一个48位计数器。在两个zero脉冲之间,一个24位参考计数器计数A/B旌旗灯号的沿数量。同时利用两个24位寄存器,其用来评价编码长度参考标识表记标帜。累加的参考计数器值也能够用控制器大概当地MCU/DSP来计较速度大概加速度。一个速率为40MHz的编码器,最大计数频次要充足撑持一个小于25ns的沿距离。第一个24位计数器的位置能够存储以及可经由过程一个内部变乱从打仗式探针引脚(TP)读出,大概经由过程iC-MD的SPI/BiSS接口读出。在一个多轴控制器使用中,这个功用有助于在tX时辰同步存储所有的位置信息, 以及次第读出传布延时工夫。图5:3通道增量编码器接口带差分RS422接收器 A/B相位逻辑也被iC-MD监控,而且陈述给MCU/DSP其他毛病,比方过压,经由过程一个毛病输出(NERR)。报警,比方计数器向上溢出大概向下溢出,由iC-MD的输出NWARN切换到低电平来标记。这些输出端子是双向的而且也由iC-MD作为一个内部动静来存储以及它的形态能够经由过程SPI/BiSS接口读出。两个施行器输出(ACT0/1)可由软件和MCU/DSP作为旌旗灯号输出(比方,用于LED形态唆使)大概作为开关。当考虑到许多编码器接口设想数不尽的应战时,设计者面临的是更多的应战。若接纳编码器处理器,比方iC-MD,许多功用能够从一个曾经存在的MCU/DSP平台得到。假如如许,这将会削减体系的承担以及提高许多机能和适应性来到达整体体系设想的要求。 5)提要  在将来的几年里,需求更短的机械消费速度和更节能的产物,并且为驱动体系开辟快速位置传感器也将成为一个次要的应战。有针对性的集成电路,如本文的这个例子,将有助于以本钱效益的方法处理这些要求。将来的编码器iC研发对准的是时钟速率高达100MHz,以便更高的精度能够被快速和可靠的丈量。 
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Going digital scanning cursor
游标插补细分为线性位移丈量体系和扭转编码器供给了优良的差分线性和更高的分辨率 混淆旌旗灯号亚微米CMOS手艺供给了高机能的片上体系设想。跟着传感器(光电二极管大概霍尔元件)的集成,提高了位置传感灵敏度。模仿正弦旌旗灯号插补细分曾经变成了一个技术标准,线性位移体系可以抵达小于1微米的分辨率。假如在这些交织距离重复使用这个道理,就会获得愈加准确的丈量成果。这种方法的基本原理来自游标卡尺,这类插补细分利用了集成游标设想。不管丈量尺是磁的大概光的,大概是大略的仍是精密的,计较道理是不异的。这个游标扫描历程是完整模仿的,而且发作在一个超小区域内。这个办法供给了替换既定的线性和扭转位置的传感办法。 一种细分编码器由比力主尺和游标细分尺,电子传感器能够获得准确的读数,不需要持续扫描多个数字轨道。比方,iC-Haus的插补细分电路iC-MN(图1)能够评价一个大概两个附加到主尺的游标尺而且结合这些读数构成位置数据。图1:光学游标体系用于三个旌旗灯号轨道插补细分关于iC-MN,插补细分电路界说绝对角度位置是操纵三个正弦旌旗灯号的相移。这种方法比仅利用两个标尺对体系要求的精度较低,较简单实现。主轨道α1决议着细分分辨率和体系绝对精度,游标轨道α3和段轨道α2发生的信息用来决议距离(图2和图3)。一步一步的计较步进时旌旗灯号毛病许可的公役。接纳这种方法能够制造小尺寸的丈量尺和编码器机构,而且这类灵活性能够用于较小的传感器。旌旗灯号的频次也低落了,因而,经由过程模仿电路元件的差别相移延时的低通特性能够疏忽,无需利用低通滤波器。图2:三正弦/余弦输入旌旗灯号别离数字化(相位角a1,a2和a3)图3:以a1供给的细分分辨率从相移a1和a2计算出角度a3芯片功用iC-MN的每一个通道有一个可调理的旌旗灯号调度单元和一个接纳连结电路,采样连结电路连结调度过的模仿旌旗灯号用于次第的数字化。为了到达这个目标,此单位包罗一个高精度SAR ADC,带8-13位可调理分辨率的插补细分器。 在模仿电路,旌旗灯号偏置电压为校准供给一个参考。此单位也评价旌旗灯号幅度,假如需求,传感器供给能量给这个轨道。这意味着在室温下调度的参数设置仍旧在全部工作温度范围内有用。 非线性ADC利用正切函数同时阐发正弦和余弦。这用来防备ADC来自细分频次依靠因为速率毛病惹起的角度毛病。 为了计较高分辨率角度位置,能够设置两个以致三个轨道游标计较,这使得分辨率高25位(360度;一周内分辨率达0.04 弧度秒)。 iC-MN为7х7mm QFN48封装,需求留意连接线终端避免极性接反和毛病毗连,包罗RS-422收发器串行数据接口。数据输出是SSI和谈大概BiSS和谈,BiSS时钟速率可达10Mbps。 利用这个器件能够监控所有的芯片主要功能和设置报警给指定功用。体系会辨认典范的传感器毛病,比方因为信号线断开惹起的旌旗灯号丧失,短路,脏污大概老化,而且告诉控制器。 光学编码器绝对值光学编码器利用精细的标尺,利用微结构应用于玻璃基片。此器件得益于体系级片上集成解决方案和元件尺寸。除了施行多轨道数字扫描之外此编码器还细分模仿旌旗灯号来发生中央值。 光学编码器利用光束穿透模式,利用LED作为光源,码盘上面有一定数量的码道,传感器为光敏感性IC。此传感器分离光电探测器,旌旗灯号调度单元和插补细分电路在一个单芯片体系。 利用一个高数目的平均距离环绕散布在码盘的圆周,尺度工艺能够到达十分高的精密分辨率。比方,片上体系iC-LG位置传感器,初始化分到达2048个相称距离每圈。码盘直径为42mm,码道宽度大要27um。 为了保持单圈绝对位置,此传感器必需辨别出每一个距离。为了到达这个目标,码盘具有高达13个附加的码道,它以数字绝对码的情势供给了明晰的距离信息。 此传感器会通过插补细分这些周期的距离来更进一步完美这个位置数据。在这里,每个距离供给了一个正弦和一个余弦旌旗灯号。经由过程计较正切函数,传感器能够肯定一个距离内实践的相角。这能够抵偿数字绝对代码的不利因素来得到更纤细的绝对位置信息,响应分辨率高达21位。 游标的诀窍为了到达精密的根本分辨率,基于游标的计较也能够辨别这些周期的距离。为了到达这个目标,这个办法利用分外的正弦旌旗灯号代替数字绝对码。关于丈量标尺,3个轨道足以替换12个。今朝的传感器,LED以及镜头都合适设想成十分小的元件,这些小尺寸的元件开拓了新的使用。 同时,有用的光电传感器阵列,比方iC-LSH,供给高保真的无滞后和低失真正弦旌旗灯号。这许可精细细分以便游标计较能基于较少的周期距离(图4)。图4:游标编码器空间缩小一半角度偏差为了到达较好的细分,确认相干旌旗灯号毛病和抵偿这些旌旗灯号是非常重要的。典范的毛病源包罗由偏置惹起的传感器壅闭(OS和OC);传感器正弦和余弦旌旗灯号的灵敏度不一致(幅度AS和AC);正弦和余弦旌旗灯号之间的相移偏离90度;(ΦSERR 和/或ΦCERR)以及传感器的非线性特性曲线(正弦和/或余弦曲线的外形偏向)。在丈量标尺大概光栅也有偏差,比方每一个周期距离的宽度颠簸招致正弦和/或余弦旌旗灯号的周期会差别。凡是这个角度由一个周期距离的反正切正弦和余弦旌旗灯号相干的商按照等式1计算出:插补细分电路量化这个角度,细分这个周期距离使得编码器的位置分辨率超越每扭转20位是可行的。一个短的颠簸角度毛病是在一个周期距离内的毛病。依赖于周期距离的数目,此毛病对角度丈量绝对精度有差别水平的影响。一个长的颠簸角度毛病跟着轴每扭转一周而反复。调解码盘凡是会惹起这类范例的毛病。丈量标尺的精度也是一个决定性的影响身分。编码器轴的装配也能够惹起全部体系的角度毛病(比方,装配偏离中心以及轴和轴承受力过大)。 关于光编码器(iC-LG,2048个周期距离),全部一圈(360度)的绝对毛病×2048)。插补细分电路能够提高10倍的精度,电子精度能够到达2.8度。为了抵偿较低分辨率的丈量标尺的旌旗灯号,对插补细分电路要求就更高。旌旗灯号调度也是一个主要的身分。它必需精密的改正波形。传感器旌旗灯号谐波重量也是一个影响插补细分成果的身分,由于它会减小角度的精度。如今制造的光电传感器阵列总谐波失真低于0.4%(利用256个周期距离),但是,曾经是一个次要的毛病滥觞。 提要好在有游标插补细分手艺,利用此手艺的编码器使得丈量体系的团体机能能够到达更高的精度以及利用优秀的差分精度为数字化的机电反应体系供给更高的分辨率。一个相对较小的光学传感器仅仅由几个少数的旌旗灯号相位干系足以扫描位置信息。利用此手艺做编码器能够利用简朴的光源,较低的功耗,和节流空间。这反过来又低落了体系本钱和开拓了新的使用。 
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