2022年AS_增量型磁旋转编码器芯片[归 .pdf

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1、Revision 1.5 Page 1 of 17 1General Description The AS5035 is a magnetic incremental encoder with 64 quadrature pulses per revolution (8-bit resolution) and index output. Two diagnostic outputs are provided to indicate an out-of-range condition of the magnetic field as well as movement of the magnet

2、in Z-axis. In addition a specific combination of output states indicate a loss of power supply. The AS5035 is available in a small 16pin SSOP package. It can be operated at either 3.3V or 5V supplies. Figure 1: Typical arrangement of AS5035 and magnet 1.1Benefits -Complete system-on-chip, including

3、analog front end and digital signal processing -2-channel quadrature and index outputs provide an alternative to optical encoders -User programmable Zero positioning by OTP allows easy assembly of magnet -Diagnostic features for operation safety -Ideal for applications in harsh environments due to m

4、agnetic sensing principle -Robust system, tolerant to magnet misalignment, air gap variations, temperature variations and external magnetic stray fields -No calibration required 2Key Features - Full turn (360) contactless angular position encoder - 2 quadrature A/B outputs with 64 pulses per revolut

5、ion (ppr), 256 edges per revolution, 1.4 per step - Index output (one pulse per revolution) - Accurate user programmable zero position (0.35) - Failure detection mode for magnet placement monitoring and loss of power supply - Wide temperature range: - 40C to + 125C - Small lead-free package: SSOP 16

6、 (5.3mm x 6.2mm) 3Applications Industrial applications: - Robotics - Replacement of optical encoders - Flow meters - Man-machine interface Automotive applications: - Power seat position sensing - Power mirror position sensing 4Pin Configuration Figure 2: AS5035 Pin configuration SSOP16AS5035 PROGRAM

7、MABLE 64 PPR INCREMENTAL MAGNETIC ROTARY ENCODERDATA SHEET名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 1 页，共 17 页 - - - - - - - - - AS5035 64 PPR INCREMENTAL MAGNETIC ROTARY ENCODER Revision 1.5 Page 2 of 17 AS5035SinCosAngMagMagINCnMagDECnChannel AChannel BIndexVD

8、D5VVDDV3VOTP_CLKOTP_DOPROGCSnLDO 3.3VHall Array&FrontendAmplifierOTPZeroPositionDSPIncrementalDecoderFigure 3: AS5035 Block diagram 4.1Pin List & Description Pin # SSOP16 Name Type AS5035 1 MagInc DO_OD Mag. Field indicator 2 MagDec DO_OD Mag. Field indicator 3 A DO Quadrature channel A 4 B DO Quadr

9、ature channel B 5 N.C. test Must be left open 6 Index DO Incremental Index output 7 VSS Supply Supply Ground 8 Prog DI , pd OTP Prog ramming Input. Internal pull-down resistor (74k). Should be connected to VSS if not used 9 OTP_DO DO_T Data Output for Zero Position programming 10 OTP_CLK DI,ST Clock

10、 Input for Zero Position programming; Schmitt-Trigger input. Should be connected to VSS if not used 11 CSn DI_ST, pu Enable outputs A,B,I (see 5.4). Connect to VSS for normal operation 12 N.C. test Must be left open 13 N.C. test Must be left open 14 N.C. test Must be left open 15 VDD3V3 Supply 3V re

11、gulator output 16 VDD5V Supply 5V positive supply input Table 1: Pin description DO_OD : digital output, open drain DO : digital push/pull output DI : digital input ST : Schmitt-Trigger input pu : internal pull-up resistor pd : internal pull-down resistor test : pin is used for factory testing, must

12、 be left unconnected 4.2Unused Pins Pins # 5, 8, 12, 13 and 14 are for factory testing and must be left unconnected Pins# 8, 9 and 10 are used for OTP Zero Position Programming only. In normal operation, they can be left open or connected to VSS (pins 8 and 10 only)名师资料总结 - - -精品资料欢迎下载 - - - - - - -

13、 - - - - - - - - - - - 名师精心整理 - - - - - - - 第 2 页，共 17 页 - - - - - - - - - AS5035 64 PPR INCREMENTAL MAGNETIC ROTARY ENCODER Revision 1.5 Page 3 of 17 5Connecting the AS5035 5.1Power Supply 5.1.15.0V Operation Connect a 4.5V to 5.5V power supply to pin VDD5V only. Add a 1 F to 10F buffer capacitor t

14、o pin VDD3V3 5.1.23.3V Operation Connect a 3.0V to 3.6 V power supply to both pins VDD5V and VDD3V3. If necessary, add a 100nF ceramic buffer capacitor to pin VDD3V3. LDOINTERFACE2.2.10F100n4.5 - 5.5VAIndexBVDD3V3VSSVDD5V5V OperationInternal VDDCSnLDO100n3.0 - 3.6VVDD3V3VSSVDD5V3.3V OperationInterna

15、l VDDINTERFACEAProgOTP_CLKOTP_DOIndexBCSnProgOTP_CLKOTP_DOFigure 4: Connections for 5V / 3.3V supply voltages 5.2Logic High and Low Levels VDD5V will be either 3.0 - 3.6V or 4.5 - 5.5V, depending on configuration. In either case, the logic levels on output pins A, B and Index will be Vout high = VDD

16、5V 0.5V, Vout low = VSS+0.4V. The logic level on the CSn input pin will be Vin high = VDD5V*0.7, Vin low = VDD5V*0.3 5.3Output Current The available maximum output current on pins A, B and Index to maintain the Vout high and Vout low levels is 2mA (sink and source) at VDD5V = 3.0V 4mA (sink and sour

17、ce) at VDD5V = 4.5V 5.4Chip Select Pin CSn 5.4.1Without Power-up Diagnostic Feature For standalone operation without microcontroller, pin CSn should be connected to VSS permanently. The incremental outputs will be available, as soon as the internal offset compensation is finished (within 50ms). 5.4.

18、2With Power-up Diagnostic Feature A diagnostic feature is available to detect a temporary loss of power or initial power-up of the AS5035: if the CSn pin is high or left open (internal pull up resistor 50k) during power-up, the incremental outputs will remain in high state: A = B = Index = High. Thi

19、s state indicates a power-up or temporary loss of power, as in normal operation A, B and Index will never be high at the same time. When Index is high, both A and B are low. To clear this state end enable the incremental outputs, CSn must be pulled low. The incremental outputs will remain enabled if

20、 CSn returns to high afterwards. 名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 3 页，共 17 页 - - - - - - - - - AS5035 64 PPR INCREMENTAL MAGNETIC ROTARY ENCODER Revision 1.5 Page 4 of 17 5.5MagInc and MagDec Indicators These two pins are open-drain outputs with a maxim

21、um driving capability of 2mA 3.0V and 4mA 4.5V. MagINC, (Magnitude Inc rease) turns on, when the magnet is pushed towards the IC, thus when the magnetic field strength is increasing.MagDEC,(Magnitude Decrease) turns on, when the magnet is pulled away from the IC, thus when the magnetic field strengt

22、h is decreasing. If both outputs are low, they indicate that the magnetic field out of the allowed range: MagINC MagDEC Description off off No distance change. Magnetic Input Field OK off on Distance increase (Magnet pulled away from IC) on off Distance decrease (Magnet pushed towards IC) on on Magn

23、etic Input Field invalid out of range: either too large (magnet too close) or too small (missing magnet or magnet too far away) Table 2: Magnetic field strength diagnostic outputs off = open-drain output transistor is off. Using a pull-up resistor, the output is high on = open-drain output transisto

24、r is on. Using a pull-up resistor, the output is low Both outputs MagInc and MagDec may be tied together, using one common pull-up resistor. In this case, the output will be high only when the magnetic field is in range. It will be low when either the magnet is moving in Z-axis or when the magnetic

25、field is out of range.6Incremental Outputs 6.1A, B and Index The phase shift between channel A and B indicates the direction of the magnet movement. Channel A leads channel B at a clockwise rotation of the magnet (top view, magnet placed above or below the device) with 90 electrical degrees. Channel

26、 B leads channel A at a counter-clockwise rotation. The Index pulse has a width of 1LSB = 1.4 6.2Hysteresis To avoid flickering of the incremental outputs at a stationary mechanical position, a hysteresis of 0.7 is introduced. When the direction of rotation is reversed, the incremental outputs will

27、not change state unless the movement in the opposite direction is larger than the hysteresis. This leads to the effect that the A,B and Index pulse positions will be shifted by 0.7 when the rotational direction is reversed. This shift is cancelled again with the next reversal of direction so that th

28、e A,B and Index pulses appear always at the same position for a given rotational direction no matter how often the rotational direction is reversed (see Figure 5). .A B Index= 1.40625 Index Mechanical Zero PositionRotation Direction ChangeCSn t Incremental outputs validHysteresis =0.7 Mechanical Zer

29、o Positionpower-up1.40625 =90e5.625 =360eFigure 5: Incremental quadrature outputs名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 4 页，共 17 页 - - - - - - - - - AS5035 64 PPR INCREMENTAL MAGNETIC ROTARY ENCODER Revision 1.5 Page 5 of 17 7Zero Position Programming Zero Po

30、sition Programming is an OTP option that simplifies assembly of a system, as the magnet does not need to be manually adjusted to the mechanical zero position. Once the assembly is completed, the mechanical and electrical zero positions can be matched by software. Any position within a full turn can

31、be defined as the permanent new index position. For Zero Position Programming, the magnet is turned to the mechanical zero position (e.g. the “off ”-position of a rotary switch) and an automatic zero position programming is applied. The zero position is programmed to an accuracy of +/- 0.35 . USBFig

32、ure 6: Hardware connection of AS5035 to AS50 xx Demoboard for Zero Position Programming 名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 5 页，共 17 页 - - - - - - - - - AS5035 64 PPR INCREMENTAL MAGNETIC ROTARY ENCODER Revision 1.5 Page 6 of 17 7.1OTP Programming TimingOT

33、P programming requires access to the factory settings register of the AS5035. Improper or accidental modification of the factory settings may render the chip unusable. Therefore the Zero Position and CCW programming is recommended only with austriamicrosystems proprietary hardware and software. Note

34、: During the programming process, the transitions in the programming current may cause high voltage spikes generated by the inductance of the connection cable. To avoid these spikes and possible damage to the IC, the connection wires, especially the signals Prog and VSS must be kept as short as poss

35、ible. The maximum wire length between the VPROG switching transistor and pin Prog (see Figure 6) should not exceed 50mm (2 inches). To suppress eventual voltage spikes, a 10nF ceramic capacitor should be connected close to pins Prog and VSS. This capacitor is only required for programming, it is not

36、 required for normal operation. The clock timing tclk must be selected at a proper rate to ensure that the signal Prog is stable at the rising edge of CLK (see Figure 7). Additionally, the programming supply voltage should be buffered with a 10F capacitor mounted close to the switching transistor. T

37、his capacitor aids in providing peak currents during programming. The specified programming voltage at pin Prog is 7.3 7.5V (see section 12.8). To compensate for the voltage drop across the VPROG switching transistor, the applied programming voltage may be set slightly higher (7.5 - 8.0V). 7.1.1CCW

38、Bit Programming The absolute angular output value, by default, increases with clockwise rotation of the magnet (top view). Setting the CCW-bit (see Figure 7) allows for reversing the indicated direction, e.g. when the magnet is placed underneath the IC: CCW = 0 angular value increases clockwise; CCW

39、 = 1 angular value increases counterclockwise. Note: Further information on the required hardware and software for Zero Position programming of the AS5035 can be found in the “AS5035” section of the austriamicrosystems website: http: (?Rotary Encoders?AS5035)Figure 7: Programming access write data (

40、first section of Figure 8) Figure 8: Complete programming sequence 名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 6 页，共 17 页 - - - - - - - - - AS5035 64 PPR INCREMENTAL MAGNETIC ROTARY ENCODER Revision 1.5 Page 7 of 17 8Simulation Modelling Figure 9: Arrangement of H

41、all sensor array on chip (principle) With reference to Figure 9, a diametrically magnetized permanent magnet is placed above or below the surface of the AS5035. The chip uses an array of Hall sensors to sample the vertical vector of a magnetic field distributed across the device package surface. The

42、 area of magnetic sensitivity is a circular locus of 1.1mm radius with respect to the center of the die. The Hall sensors in the area of magnetic sensitivity are grouped and configured such that orthogonally related components of the magnetic fields are sampled differentially. The differential signa

43、l Y1-Y2 will give a sine vector of the magnetic field. The differential signal X1-X2 will give an orthogonally related cosine vector of the magnetic field. The angular displacement () of the magnetic source with reference to the Hall sensor array may then be modelled by: ()()-=5.02121arctanXXYYThe 0

44、.5 angular error assumes a magnet optimally aligned over the center of the die and is a result of gain mismatch errors of the AS5035. Placement tolerances of the die within the package are 0.235mm in X and Y direction, using a reference point of the edge of pin #1 (Figure 11) In order to neglect the

45、 influence of external disturbing magnetic fields, a robust differential sampling and ratiometric calculation algorithm has been implemented. The differential sampling of the sine and cosine vectors removes any common mode error due to DC components introduced by the magnetic source itself or extern

46、al disturbing magnetic fields. A ratiometric division of the sine and cosine vectors removes the need for an accurate absolute magnitude of the magnetic field and thus accurate Z-axis alignment of the magnetic source. The recommended differential input range of the magnetic field strength (B(X1-X2),

47、B(Y1-Y2) is 75mT at the surface of the die. In addition to this range, an additional offset of 5mT, caused by unwanted external stray fields is allowed. The chip will continue to operate, but with degraded output linearity, if the signal field strength is outside the recommended range. Too strong ma

48、gnetic fields will introduce errors due to saturation effects in the internal preamplifiers. Too weak magnetic fields will introduce errors due to noise becoming more dominant. 9Choosing the Proper Magnet Typically the magnet should be 6mm in diameter and 2.5mm in height. Magnetic materials such as

49、rare earth AlNiCo, SmCo5 or NdFeB are recommended. Magnet axisVertical fieldcomponent (45 75mT)0360360BvVertical fieldcomponentR1 concentric circle;radius 1.1mmR1Magnet axistyp. 6mm diameterSNFigure 10: Typical magnet and magnetic field distribution AS5040 die 1Radius of circular Hall sensor array:

50、1.1mm radius Center of die 2.433 mm 0.235mm 3.9 mm 0.235mm X1 Y1 X2 Y2 名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 7 页，共 17 页 - - - - - - - - - AS5035 64 PPR INCREMENTAL MAGNETIC ROTARY ENCODER Revision 1.5 Page 8 of 17 The magnet s field strength perpendicular to