austriamicrosystems AG is now ams AG The technical content of this austriamicrosystems datasheet is still valid. Contact information: Headquarters: ams AG Tobelbaderstrasse 30 8141 Unterpremstaetten, Austria Tel: +43 (0) 3136 500 0 e-Mail: [email protected] Please visit our website at www.ams.com D atas hee t AS5130 8-Bit Programmable Magnetic Rotary Encoder with Motion Detection & Multiturn 2 Key Features Two digital 8-bit absolute outputs: - Serial interface - Pulse width modulated (PWM) output User programmable zero position High speed: up to 30000 rpm al id 360º contactless angular position encoding Failure detection mode for magnet placement monitoring and loss of power supply Wide temperature range: -40ºC to +125ºC am lc s on A te G nt st il The AS5130 is a contactless magnetic rotary encoder for accurate angular measurement over a full turn of 360º. It is a system-on-chip, combining integrated Hall elements, analog front end and digital signal processing in a single device. The angle can be measured using only a simple two-pole magnet rotating over the center of the chip. The magnet may be placed above or below the IC. The absolute angle measurement provides instant indication of the magnet’s angular position with a resolution of 8 bit = 256 positions per revolution. This digital data is available as a serial bit stream and as a PWM signal. The AS5130 can be operated in pulsed mode (Vsupply=off), which reduces the average power consumption significantly. During Vsupply=off, the measured angle can be stored using an internal storage register supplied by a low power voltage line. This mode achieves very low power consumption during polling of the rotary position of the magnet. If the position of the magnet changes, then the motion detection feature wakes up an external system. The device is capable of counting the amount of magnet revolutions. The multi turn counter value is stored in a register and can be read in addition to the angle information. Furthermore, any arbitrary position can be set as zero-position. The system is tolerant to misalignment, air gap variations, temperature variations and external magnetic fields and high reliability due to non-contact sensing. lv 1 General Description Multi Turn counter / Movement detection Small Pb-free package: SSOP-16 (5.3mm x 6.2mm) Automotive qualified to AEC-Q100, grade 1 3 Applications The AS5130 is an ideal solution for Ignition key position sensing, Steering wheel position sensing, Transmission gearbox encoder, Front panel rotary switches and replacement of Potentiometers. Figure 1. AS5130 Block Diagram ca SINP / SINN / COSP / COSN AS5130 PWM Decoder PWM Ang ni Sin Hall Array & Frontend Amplifier Te Zero Postion Tracking ADC & Angle Decoder ch Cos Absolute Serial Interface (SSI) Mag DIO CS DCLK C1 AGC AGC Power Management www.austriamicrosystems.com/AS5130 CAO OTP Revision 1.12 PROG 1 - 41 AS5130 Datasheet - C o n t e n t s Contents 1 2 Key Features............................................................................................................................................................................. 1 3 Applications............................................................................................................................................................................... 1 4 Pin Assignments ....................................................................................................................................................................... 4 4.1 Pin Descriptions.................................................................................................................................................................................... 4 al id 1 General Description .................................................................................................................................................................. 5 Absolute Maximum Ratings ...................................................................................................................................................... 5 6 Electrical Characteristics........................................................................................................................................................... 6 8 8 7 Detailed Description.................................................................................................................................................................. 9 7.1 Connecting the AS5130........................................................................................................................................................................ 9 Serial 3-Wire Connection (Default Setting).................................................................................................................................. 9 Serial 3-Wire Connection (OTP Programming Option).............................................................................................................. 11 1-Wire PWM Connection ........................................................................................................................................................... 11 Analog Output............................................................................................................................................................................ 12 Analog Sin/Cos Outputs with External Interpolator.................................................................................................................... 13 am lc s on A te G nt st il 7.1.1 7.1.2 7.1.3 7.1.4 7.1.5 lv 6.1 Timing Characteristics .......................................................................................................................................................................... 6.2 Magnetic Input Range .......................................................................................................................................................................... 7.2 Serial Synchronous Interface (SSI) .................................................................................................................................................... 15 7.2.1 Commands of the SSI in Normal Mode ..................................................................................................................................... 15 7.2.2 Commands of the SSI in Extended Mode.................................................................................................................................. 16 7.3 OTP Programming.............................................................................................................................................................................. 17 7.4 Multi Turn Counter.............................................................................................................................................................................. 19 7.5 AS5130 Status Indicators ................................................................................................................................................................... 19 7.5.1 Lock Status Bit........................................................................................................................................................................... 19 7.5.2 Magnetic Field Strength Indicators ............................................................................................................................................ 19 7.6 “Pushbutton” Feature.......................................................................................................................................................................... 7.7 High Speed Operation ........................................................................................................................................................................ Propagation Delay ..................................................................................................................................................................... Sampling Rate ........................................................................................................................................................................... Chip Internal Lowpass Filtering ................................................................................................................................................. Digital Readout Rate.................................................................................................................................................................. Total Propagation Delay of the AS5130 .................................................................................................................................... ca 7.7.1 7.7.2 7.7.3 7.7.4 7.7.5 7.8 Reduced Power Modes ...................................................................................................................................................................... 20 21 21 21 21 21 21 22 ni 7.8.1 Low Power Mode ....................................................................................................................................................................... 22 7.8.2 Power Cycling Mode.................................................................................................................................................................. 23 7.8.3 Polling Mode .............................................................................................................................................................................. 24 ch 8 Application Information ........................................................................................................................................................... 27 27 8.2 Application Example II: Low-Power Encoder...................................................................................................................................... 28 8.3 Application Example III: Polling Mode ................................................................................................................................................ 29 Te 8.1 Application Example I: 3-Wire Sensor with Magnetic Field Strength Indication ................................................................................. www.austriamicrosystems.com/AS5130 Revision 1.12 2 - 41 AS5130 Datasheet - C o n t e n t s 8.4 Accuracy of the Encoder System ....................................................................................................................................................... Quantization Error...................................................................................................................................................................... Vertical Distance of the Magnet................................................................................................................................................. Choosing the Proper Magnet..................................................................................................................................................... Magnet Placement..................................................................................................................................................................... Lateral Displacement of the Magnet .......................................................................................................................................... Magnet Size............................................................................................................................................................................... 30 32 33 34 35 36 al id 8.4.1 8.4.2 8.4.3 8.4.4 8.4.5 8.4.6 30 9 Package Drawings and Markings ........................................................................................................................................... 37 9.1 Recommended PCB Footprint............................................................................................................................................................ 40 Te ch ni ca am lc s on A te G nt st il lv 10 Ordering Information............................................................................................................................................................. 38 www.austriamicrosystems.com/AS5130 Revision 1.12 3 - 41 AS5130 Datasheet - P i n A s s i g n m e n t s 4 Pin Assignments 1 16 DVDD PROG 2 15 PWM VSS 3 14 WAKE SINP 4 13 C1 SINN 5 12 VDD COSP 6 11 DIO COSN 7 10 CS TestCoil 8 9 am lc s on A te G nt st il AS5130 lv CAO al id Figure 2. Pin Assignments (Top View) DCLK 4.1 Pin Descriptions Pin Name CAO PROG VSS SINP SINN COSP COSN Description 1 Indicates if the magnetic field is present. If the field is too low, the signal is HI. 2 OTP Programming Pad, programming voltage. For normal operation it must be left unconnected. 3 Supply Ground. 4 Used for factory testing. For normal operation it must be left unconnected. 5 Used for factory testing. For normal operation it must be left unconnected. 6 Used for factory testing. For normal operation it must be left unconnected. 7 Used for factory testing. For normal operation it must be left unconnected. 8 Test pin. Must be left unconnected. ni Test Coil Pin Number ca Table 1. Pin Descriptions 9 Clock Source for SSI communication. Schmitt trigger input. CS 10 Chip Select for SSI. Active high. Schmitt trigger input. DIO 11 Data input / output for SSI communication. VDD 12 Positive Supply Voltage 5V. C1 13 Test mode selector. For normal operation it must be connected to VSS. WAKE 14 Interrupt output. Used for polling mode. Open Drain NMOS. Use pull-up resistor with >1.5kΩ. PWM 15 Pulse Width Modulation output. 0.5µs width step per LSB. 16 Pin to connect to low power supply for polling mode. Must be connected to VSS in normal mode. Te ch DCLK DVDD www.austriamicrosystems.com/AS5130 Revision 1.12 4 - 41 AS5130 Datasheet - A b s o l u t e M a x i m u m R a t i n g s 5 Absolute Maximum Ratings Stresses beyond those listed in Table 2 may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in Electrical Characteristics on page 6 is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Table 2. Absolute Maximum Ratings Min Max Units Comments Supply Voltage 0.3 7 V Only relevant for polling operation mode, supply voltage with capacitor of the integrated storage register during toff phase of VDD Input Pin Voltage VSS-0.5 VDD V Input Current (latchup immunity) -100 100 mA Norm: EIA/JESD78 ClassII Level A ±2 kV Norm: JESD22-A114E 168 K/W Still Air / Single Layer PCB Package Thermal Resistance SSOP-16 133 -55 150 ºC -40 125 ºC 150 ºC am lc s on A te G nt st il Storage Temperature Ambient Temperature lv Electrostatic Discharge al id Parameter Junction Temperature Package body temperature Humidity non-condensing 5 ºC 85 % 3 Represents a maximum floor life time of 168h Te ch ni ca Moisture Sensitivity Level (MSL) 260 Norm: IPC/JEDEC J-STD-020. The reflow peak soldering temperature (body temperature) specified is in accordance with IPC/ JEDEC J-STD-020 “Moisture/Reflow Sensitivity Classification for Non-Hermetic Solid State Surface Mount Devices”. The lead finish for Pb-free leaded packages is matte tin (100% Sn). www.austriamicrosystems.com/AS5130 Revision 1.12 5 - 41 AS5130 Datasheet - E l e c t r i c a l C h a r a c t e r i s t i c s 6 Electrical Characteristics TAMB = -40ºC to +125ºC, unless otherwise noted. Table 3. Electrical Characteristics Parameter Conditions Min Typ Max Units VDD Positive Supply Voltage Except OTP programming 4.5 5 5.5 V DVDD Polling Mode Supply Voltage 3.6 5 5.5 V IDD Power Supply Current 14 24 mA Ioff Power Down Mode 2 mA N Resolution 1.4 8 Startup from zero deg 2000 Startup with preset AGC - Polling mode (Supplied during toff phase of VDD from the external buffer capacitor via DVDD pin) 250 am lc s on A te G nt st il Power Up Time TPwrUp bit lv 1.406 al id Symbol Startup from low power mode 150 tda Propagation Delay Analog signal path; over full temperature range tdd Tracking rate Step rate of tracking ADC; 1 step = 1.406º tdelay Signal Processing Delay Total signal processing delay, Analog + Digital + SSI readout (tda + tdd + tSSI) T Analog filter time constant Internal lowpass filter 4.1 Centered Magnet -2 2 Accuracy Within horizontal displacement radius (see parameters for magnet) -3 3 Transition Noise rms (1 sigma) INLcm TN PORr Power-On-Reset levels PORf ca Parameters for Magnet 1.15 1.45 µs 21.55 µs 12.5 µs 6.6 0.235 4,3 V VDD falling 3.4 3.7 3.9 V -30000 30000 rpm MD Magnet diameter Diametrically magnetized MT Magnet thickness ni µs 4 Frequencies above 1000 rpm causes an additional not specified DNL Error 6 mm 2.5 mm Magnetic input range Valid for use of full range of sensitivity 32 75 mT Magnetic Sensitivity of AGC AGC value available at SSI 0.5 5 LSB/mT Magnetic Offset Magnetic stray field without gradient 4 mT ch BDC 17 3.7 Rotational Speed s 0.85 15 VDD rising n Bi µs DC/AC Characteristics for Digital Inputs and Outputs Te CMOS Input 0.7 x VDD VIH High level Input voltage VIL Low level Input Voltage 0.3 x VDD V ILEAK Input Leakage Current 1 µA V CMOS Output www.austriamicrosystems.com/AS5130 Revision 1.12 6 - 41 AS5130 Datasheet - E l e c t r i c a l C h a r a c t e r i s t i c s Table 3. Electrical Characteristics (Continued) Symbol Parameter Conditions Min Typ Max VOH High level Output voltage VOL Low level Output Voltage VSS + 0.4 V CL Capacitive Load 35 pF tslew Slew Rate tdelay Time Rise Fall Vout_wake up Wake up output VDD 0.5 Units al id V Open drain output with tri-state behavior Programming Parameters 30 ns 15 ns 5 V 8.5 V 100 mA lv External capacitive load C_L = 35pF External series resistance R = 0Ω Junction temperature TJ = 136ºC Rise time of the internal driver t_rise = 3ns Fall time of the internal driver t_fall = 3ns VPROG Programming Voltage IPROG Programming Current TambPROG Programming ambient temperature During programming 0 85 ºC tPROG Programming time Timing is internally generated 2 4 µs Analog readback voltage During Analog Readback mode at pin PROG VR,unprog WakeLSB Angle difference threshold for wake up Factory setting is 4 LSB, value is accessible by SSI in buffered register and can be generation changed by customer. 8-bit PWM output 8.0 am lc s on A te G nt st il VR,prog Static voltage at pin PROG 0.5 2.2 3.5 0 127 V LSB PWM resolution PWMIN PWM pulse width Angle = 0º (00H) 0.71 0.55 0.43 µs PWMAX PWM pulse width Angle = 358.6º (FFH) 182.88 142.24 108.48 µs PWP PWM Period Over full temperature range 183.6 142.8 108.9 µs fPWM PWM Frequency =1 / PWM period 5.44 7 9.18 kHz Hyst Digital hysteresis At change of rotation direction Serial 8-bit Output fCLK Normal operation Clock Frequency During OTP programming 1 6 166.6 250 bit bit MHz ns 500 kHz Te ch fCLK, P 8 Clock Frequency ni tCLK ca NPWM www.austriamicrosystems.com/AS5130 Revision 1.12 7 - 41 AS5130 Datasheet - E l e c t r i c a l C h a r a c t e r i s t i c s 6.1 Timing Characteristics TAMB = -40ºC to 125ºC, unless otherwise noted. Table 4. Timing Characteristics Rising CLK to CS t1 Min Typ Max Units 15 -- ns Chip select to positive edge of CLK 15 -- ns t2 Chip select to drive bus externally -- -- ns t3 Setup time command bit, Data valid to positive edge of CLK 30 t4 Hold time command bit, Data valid after positive edge of CLK 30 t5 Float time, Positive edge of CLK for last command bit to bus float 30 t6 Bus driving time, Positive edge of CLK for last command bit to bus drive CLK/2 +0 CLK/2 +30 ns t7 Setup time data bit, Data valid to positive edge of CLK CLK/2 +0 CLK/2 +30 ns t8 Hold time data bit, Data valid after positive edge of CLK CLK/2 +0 CLK/2 +30 ns t9 Hold time chip select, Positive edge CLK to negative edge of chip select 30 t10 Bus floating time, Negative edge of chip select to float bus 0 30 ns tTO Timeout period in 2-wire mode (from rising edge of CLK) 20 24 µs al id t0 Conditions ns ns lv Parameter CLK/2 ns am lc s on A te G nt st il Symbol ns 6.2 Magnetic Input Range The magnetic input range is defined by the AGC loop. This regulating loop keeps the Hall sensor output in the optimum range for low SNR by adjusting the Hall bias current. This loop can adjust to a magnetic field strength variation of ±38%. The AGC output voltage is an indicator for the magnetic field. ca The nominal magnetic field for a balanced AGC is defined by the Hall bias and the Hall sensitivity and can be set by a variable gain in the signal path. The gain can be set in 8 steps in the OTP or by the SSI in a mirror register. The resulting magnetic input range is a value of Bnominal±38% inside of a range of 32mT …75mT, if the trimming is performed by the customer. Setting ni Table 5. Magnetic Input Range 0 1 2 3 4 5 6 7 000 001 010 011 100 101 110 111 Gain A 0.9 1.05 1.2 1.4 1.65 1.9 2.2 2.55 Blimit Max. 75mT Min. 32mT Te ch Binary www.austriamicrosystems.com/AS5130 Revision 1.12 8 - 41 AS5130 Datasheet - D e t a i l e d D e s c r i p t i o n 7 Detailed Description am lc s on A te G nt st il lv al id Figure 3. Typical Arrangement of AS5130 and Magnet 7.1 Connecting the AS5130 The AS5130 can be connected to an external controller in several ways as listed below: Serial 3-wire connection (default setting) Serial 3-wire connection (OTP programming option) 1-wire PWM connection Analog output Analog Sin/Cos outputs with external interpolator 7.1.1 Serial 3-Wire Connection (Default Setting) ca In this mode, the AS5130 is connected to the external controller via three SSI signals: Chip Select (CS), Clock (CLK) input and DIO (Data) in/ output. This configuration not only helps to read and write data but also defines different operation modes. The data transfer in all cases is done via the DIO port. Te ch ni Figure 4. Standard SSI Serial Data Interface +5V VDD VDD VDD CS 100n AS5130 AS5130 micro controller CLK DIO VSS VSS VSS www.austriamicrosystems.com/AS5130 Revision 1.12 9 - 41 AS5130 Datasheet - D e t a i l e d D e s c r i p t i o n Figure 5. Normal Operation Mode CMD_PHASE DATA_PHASE READ: Device to µC WRITE: µC to Device t1 al id DCLK t9 CS t5 CMD4 t3 CMD3 CMD2 CMD1 t4 DIO CMD0 t6 CMD t7 t8 D15 t10 D14 lv t2 DIO D0 D13 t11 t13 t12 am lc s on A te G nt st il DIO READ D15 D13 D14 D0 WRITE Table 6. Serial Bit Sequence (16-bit read/write) Write Command C4 C3 C2 C1 Read/Write Data C0 D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 Figure 6. Extended Operation Mode (for access of OTP only) DATA_PHASE CMD_PHASE t1 CS t2 DIO t5 CMD3 CMD2 CMD1 ni CMD4 t3 t4 t7 CMD0 CMD t8 t6 t10 D44 D45 ch DIO t9 ca DCLK t11 READ D0 t12 DIO t13 D45 D44 WRITE Te D0 Table 7. Serial Bit Sequence (16-bit read/write) Write Command C4 C3 C2 C1 Read/Write Data C0 D15 www.austriamicrosystems.com/AS5130 D14 D13 D12 D11 D10 D9 Revision 1.12 D8 D7 D6 D5 D4 D3 D2 D1 D0 10 - 41 AS5130 Datasheet - D e t a i l e d D e s c r i p t i o n 7.1.2 Serial 3-Wire Connection (OTP Programming Option) This mode provides with an option to configure the serial interface for programming the OTP register. Using a clock input (CLK), DIO (Data) in/ output and CS pin, it is possible to write and read out data from the OTP Register. The data transfer is done via the DIO channel. For programming, the PROG pin must be connected to +8V. Analog readout for trimming verification is mandatory. al id Figure 7. Serial Data Transmission in Continuous Readout Mode +5V VDD VDD Output VDD Output I/O DIO 8.0 - 8.5V PROG C1 AS5130 AS5130 100n am lc s on A te G nt st il micro controller DCLK lv CS + VSS 10µF 100n VSS - VSS Note: For further details on OTP programming, please refer to OTP Programming (page 17). 7.1.3 1-Wire PWM Connection If the line (PWM) is used as angle output, the total number of connections can be reduced to three, including the supply lines. This type of configuration is especially useful for remote sensors. Low power mode is not possible in this configuration. If the AS5130 angular data is invalid, the PWM output will remain at low state. 100n Te ch ni ca Figure 8. Data Transmission with Pulse Width Modulated (PWM) Output www.austriamicrosystems.com/AS5130 +5V VDD VDD VDD AS5130 micro controller PWM VSS VSS VSS Revision 1.12 11 - 41 AS5130 Datasheet - D e t a i l e d D e s c r i p t i o n The minimum PWM pulse width tON (PWM = high) is 1 LSB @ 0º (Angle reading = 00H). 1LSB = nom. ,0.556µs. The PWM pulse width increases with 1LSB per step. At the maximum angle 358.6º (Angle reading = FFH), the pulse width tON (PWM = high) is 256 LSB and the pause width tOFF (PWM = low) is 1 LSB. This leads to a total period (tON + tOFF) of 257LSB. PWM out 71.7µs 0.556µs 142.3µs ton 142.3µs 0.556µs 71.15µs toff lv 5V al id Figure 9. PWM Output Signal Position 255 128 am lc s on A te G nt st il 0 Table 8. PWM Signal Parameters Position Angle LSB @ High t_high Low Column t_low Duty-Cycle 0 0º 1 0.556µs 256 142.3µs 0.39% 127 178.59º 128 71.15µs 129 71.7µs 49.4% 128 180º 129 71.7µs 128 71.15µs 50.2% 358.59º 256 142.3µs 1 0.556µs 99.6% 255 This means that the PWM pulse width is (position + 1) LSB, where position is 0….255. The tolerance of the absolute pulse width and frequency can be eliminated by calculating the angle with the duty cycle rather than with the absolute pulse width: t ON angle [ 8 - bit ] = ⎛ 257 --------------------------⎞ -1 ⎝ t ON + t OFF⎠ (EQ 1) ca results in an 8-bit value from 00H to FFH, t ON ⎞ ⎛ 257 -------------------------–1 ⎝ t ON + t OFF⎠ (EQ 2) ni 360 angle [ º ] = --------256 results in a degree value from 0º ...358.6º ch Note: The absolute frequency tolerance is eliminated by dividing tON by (tON+TOFF), as the change of the absolute timing effects both TON and TOFF in the same way. 7.1.4 Analog Output Te The AS5130 can generate a ratiometric analog output voltage by low-pass filtering the PWM output. Figure 10 shows a simple passive 2nd order low pass filter as an example. In order to minimize the ripple on the analog output, the cut-off frequency of the low pass filter should be well below the PWM base frequency. www.austriamicrosystems.com/AS5130 Revision 1.12 12 - 41 AS5130 Datasheet - D e t a i l e d D e s c r i p t i o n Figure 10. Ratiometric Analog Output +5V VDD R≥4k7 C≥1µF PWM analog out VSS micro controller VSS lv AS5130 100n al id VDD VDD am lc s on A te G nt st il VSS 5V Analog out 0V PWMout Angle 0º 360º Analog Sin/Cos Outputs with External Interpolator ca 7.1.5 180º ni By connecting C1 to VDD, the AS5130 provides analog Sine and Cosine outputs (SINP, COSP) of the Hall array front-end for test purposes. These outputs allow the user to perform the angle calculation by an external ADC + µC, e.g. to compute the angle with a high resolution. In addition, the inverted Sinus and Cosine signals (SINN, COSN; see dotted lines) are available for differential signal transmission. The input resistance of the receiving amplifier or ADC should be greater than 100kΩ. The signal lines should be kept as short as possible, longer lines should be shielded in order to achieve best noise performance. ch The SINN / COSN / SINP / COSP signals are amplitude controlled to ~1.3Vp (differential) by the internal AGC controller. The DC bias voltage is 2.25 V. Te If the SINN and COSN outputs cannot be sampled simultaneously, it is recommended to disable the automatic gain control (see Table 9) as the signal amplitudes may be changing between two readings of the external ADC. This may lead to less accurate results. www.austriamicrosystems.com/AS5130 Revision 1.12 13 - 41 AS5130 Datasheet - D e t a i l e d D e s c r i p t i o n VDD C1 VDD D A SINN SINP D A COSN COSP micro controller AS5130 AS5130 VSS am lc s on A te G nt st il VSS 100n lv +5V VDD al id Figure 11. Sine and Cosine Outputs for External Angle Calculation Te ch ni ca VSS www.austriamicrosystems.com/AS5130 Revision 1.12 14 - 41 AS5130 Datasheet - D e t a i l e d D e s c r i p t i o n 7.2 Serial Synchronous Interface (SSI) 7.2.1 Commands of the SSI in Normal Mode Table 9. SSI in Normal Mode mode 23 22 WRITE CUST 10111 write WD2COS 10110 write 21 SET TEST CFG1 10101 write 20 reserved 10100 write 19 HYST_RST 10011 write 18 WD2SIN 10010 17 WRITE CONFIG 16 -- 7 READ CUST 00111 6 RD2COS 00110 4 RD_BOTH 00100 3 STORE REF 00011 2 RD2SIN 00010 5 15 14 xen_7 inv_7 write xen_7 inv_7 10001 write go2sle ep 10000 write RD_MULTI 00001 0 RD_ANGLE 00000 11 10 9 8 7 6 5 4 3 gain <2:0> xen_6 inv_6 xen_5 inv_5 rst_m ulti nc inv_5 read read inv_7 gain <2:0> xen_6 inv_6 xen_5 inv_5 0 xen_4 inv_4 xen_3 inv_3 xen_2 inv_2 xen_1 inv_1 xen_0 inv_0 wlsb <6:0> xen_7 1 nc setHy st xen_6 inv_6 xen_5 2 xen_4 inv_4 xen_3 inv_3 xen_2 inv_2 xen_1 inv_1 xen_0 inv_0 gen_r st nc 1 12 wlsb <6:0> rst_otp 00101 13 al id bin lv cmd am lc s on A te G nt st il # nc parity xen_4 inv_4 xen_3 inv_3 xen_2 inv_2 xen_1 inv_1 xen_0 inv_0 read read Multiturn <7:0> read store_ vdd_ok reg_s ok et read xen_7 inv_7 angle <7:0> nc xen_6 inv_6 xen_5 angle_stored <7:0> inv_5 parity xen_4 inv_4 xen_3 inv_3 xen_2 inv_2 xen_1 inv_1 xen_0 inv_0 read lock agc <5:0> Multiturn <7:0> parity read lock agc <5:0> angle <7:0> parity WD2COS / WD2SIN: xen_X disables Hall element X from the sensor array in the cosine or sine channel; xinv_X inverts the voltage output of Hall element X in the channels. RD2COS / RD2SIN: The Hall array configuration for cosine and sine channel can be read out by these commands, initial values are 0. SET TEST CFG 1: gen_rst HI triggers a digital reset. WRITE CONFIG: go2sleep HI activates the low power mode of the AS5130. The power consumption is significantly reduced. go2sleep LO returns to normal operation mode. During low power mode, the lock bit in command 0 and command 1 is LO. ca WRITE CUST: With “wlsb_x” the threshold level for generation of a WAKE pulse is set (only important in polling mode). The initial value is 4 LSB. No value lower than 4 LSB can be set. The maximum value is 127 LSB. “gain_x” sets the gain in the signal ni HYST_RST: “setHyst” enables an additional hysteresis of the digital output signal. It is enabled by default. Only after 2 consecutive equal signals the output is changed. “rst_otp” forces the IC to read out the OTP in polling mode. This reset has to be performed after initial startup and every WAKE signal. ch “rst_multi” resets the multi turn counter to 0. READ CUST: With this command “wlsb_x” and “gain_x” can be read out. RD_BOTH: Angle and multi turn counter value can be read out simultaneously by this command. Due to limited data size, the parity bit is not available in this command. Te STORE REF: This command stores the actual angle as reference angle in the storage registers (only important in polling mode). The output is the stored angle (angle_stored), a flag, if the voltage at DVDD is OK (store_ok), a flag, if the supply voltage is OK (vdd_ok) and a check bit, if the register was written. RD_MULTI: Command for read out of multi turn register (multiturn) and AGC value (agc). “Lock” indicates a locked ADC and “parity” an even parity checksum. RD_ANGLE: Command for read out of angle value and AGC value (agc). “Lock” indicates a locked ADC and “parity” an even parity checksum. www.austriamicrosystems.com/AS5130 Revision 1.12 15 - 41 AS5130 Datasheet - D e t a i l e d D e s c r i p t i o n 7.2.2 Commands of the SSI in Extended Mode For programming or readout of the OTP data, the chip has to be started with DVDD at a low voltage (polling mode off or cap discharged) or the OTP reset has to be performed. If not, the OTP is not read out and the OTP data is not available. Table 10. SSI in Extended Mode cmd bin mode <45:44> 31 WRITE_O TP 11111 xt write OTP Test 30 11110 xt write 29 11101 xt write xt write 11011 xt write 11010 xt write 11001 xt write 24 11000 xt write 15 01111 xt read 14 01110 xt read 13 01101 xt read 12 01100 xt read 11 01011 xt read 10 01010 xt read 01001 xt read 01000 xt read 26 25 9 8 PROG_OT P RD_OTP_ ANA <27:26> <25> <24:23> <22:20> <19:16> <15:12> <11:9> <8> <7:0> ID OTP lock VREF Hall Bias Osc Redundan Sensitivi cy ty Wake enable Zero Angle OTP Test ID OTP lock VREF Hall Bias Osc Redundan Sensitivi cy ty Wake enable Zero Angle OTP Test ID OTP lock VREF Hall Bias Osc Redundan Sensitivi cy ty Wake enable Zero Angle lv 11100 27 <31:28> am lc s on A te G nt st il 28 <43:32> al id # WRITE OTP: Writing of the OTP register. The written data is volatile. “Zero Angle” is the angle, which is set for zero position. “Wake enable” enables the polling mode. “Sensitivity” is the gain setting in the signal path. “Redundancy is a number of bits, which allows the customer to overwrite one of the customer OTP bits <0:11>. PROG_OTP: Programming of the OTP register. Only Bits <0:15> can be programmed by the customer. RD_OTP: Read out the content of the OTP register. Data written by WRITE_OTP and PROG_OTP is read out. Te ch ni ca RD_OTP_ANA: Analog read out mode. The analog value of every OTP bit is available at pin 2 (PROG), which allows for a verification of the fuse process. No data is available at the SSI. www.austriamicrosystems.com/AS5130 Revision 1.12 16 - 41 AS5130 Datasheet - D e t a i l e d D e s c r i p t i o n 7.3 OTP Programming For programming of the OTP, an additional voltage has to be applied to the pin PROG. It has to be buffered by a fast 100nF capacitor (ceramic) and a 10µF capacitor. The information to be programmed is set by command 25. The OTP bits 16 to 45 are used for AMS factory trimming and cannot be overwritten. al id Figure 12. OTP Programming Connection +5V VDD VDD Output Output micro controller DCLK I/O AS5130 AS5130 DIO am lc s on A te G nt st il 8.0 - 8.5V 100n lv VDD CS + VSS 10µF 100n PROG C1 VSS - VSS Figure 13. External Circuitry for OTP Programming maximum parasitic cable inductance VSUPPLY L<50nH Vzapp ca C1 C2 PROG GND PROM Cell 10µF ch ni 100nF VDD Vprog Table 11. OTP Programming Parameters Parameter Min Max Unit VDD Supply Voltage 5 5.5 V GND Ground Level 0 0 V V_zapp Programming Voltage 8 8.5 V T_zapp Temperature 0 85 ºC f_clk CLK Frequency 100 kHz Te Symbol www.austriamicrosystems.com/AS5130 Revision 1.12 Notes At pin PROG At pin DCLK 17 - 41 AS5130 Datasheet - D e t a i l e d D e s c r i p t i o n Programming Verification. After programming, the programmed OTP bits are verified in following two ways: By Digital Verification: This is simply done by sending a READ OTP command (#0FH, Refer to Table 10). The structure of this register is the same as for the OTP PROG or OTP WRITE commands. By Analog Verification: By sending an ANALOG OTP READ command (#09H), pin PROG becomes an output, sending an analog voltage with each clock, representing a sequence of the bits in the OTP register. A voltage of <500mV indicates a correctly programmed bit (“1”) while a voltage level between 2.2V and 3.5V indicates a correctly unprogrammed bit (“0”). Any voltage level in between indicates improper programming. al id Figure 14. Analog OTP Verification lv +5V VDD VDD VDD Output am lc s on A te G nt st il CS Output micro controller CLK I/O AS5130 AS5130 DIO 100n PROG VSS V C1 VSS VSS Redundancy Decoding. If a bit is not fused properly (analog readout levels violated), the redundancy bits can be used as shown in the table replaced bit <15:12> replaced bit none 1000 7 0 1001 8 1 1010 9 ni below. Only one single bit can be overwritten with a logic HI. An improper fusing cannot be made undone. <15:12> 2 1011 10 3 1100 11 4 1101 none 0110 5 1110 none 0111 6 1111 none ca 0000 0001 0010 0011 0100 Te ch 0101 www.austriamicrosystems.com/AS5130 Revision 1.12 18 - 41 AS5130 Datasheet - D e t a i l e d D e s c r i p t i o n 7.4 Multi Turn Counter An 8-bit register is used for counting the magnet’s revolutions. With each zero transition in any direction, the output of a special counter is incremented or decremented. The initial value after reset is 0 LSB. The multi turn value is encoded as complement on two. Clockwise rotation gives increasing angle values and positive turn count. Counter clockwise rotation exhibits decreasing angle values and a negative turn count respectively. Decimal Value 01111111 127 --- --- 00000011 +3 00000010 +2 00000001 +1 00000000 0 11111111 -1 11111110 -2 11111101 -3 --- --- 10000000 -128 am lc s on A te G nt st il lv al id Bit Code The counter output can be reset by using command 19 – HYST_RST. It is immediately reset by the rising clock edge of this bit. Any zero crossing between the clock edge and the next counter readout changes the counter value. 7.5 AS5130 Status Indicators 7.5.1 Lock Status Bit The Lock signal indicates whether the angle information is valid (ADC locked, Lock = high) or invalid (ADC unlocked, Lock = low). To determine a valid angular signal at best performance, the following indicators should be set: Lock = 1 0x00h < AGC < 0x2Fh 7.5.2 ca Note: The angle signal may also be valid (Lock = 1), when the AGC is out of range (00H or 2FH), but the accuracy of the AS5130 may be reduced due to the out of range condition of the magnetic field strength. Magnetic Field Strength Indicators ni The AS5130 is not only able to sense the angle of a rotating magnet, it can also measure the magnetic field strength (and hence the vertical distance) of the magnet. This additional feature can be used for several purposes: ch - as a safety feature by constantly monitoring the presence and proper vertical distance of the magnet - as a state-of-health indicator, e.g. for a power-up self test - as a pushbutton feature for rotate-and-push types of manual input devices The magnetic field strength information is available in two forms – Magnetic field strength hardware indicator and Magnetic field strength software indicator. Te Magnetic Field Strength Hardware Indicator. Pin CAO (#1) will be low, when the magnetic field is too weak. The switching limit is determined by the value of the AGC. If the AGC value is <3FH, the CAO output will be high (green range), If the AGC is at its upper limit (3FH), the CAO output will be low (red range). Magnetic Field Strength Software Indicator. D13:D7 in the serial data that is obtained by command READ ANGLE (see Table 9) contains the 6-bit AGC information. The AGC is an automatic gain control that adjusts the internal signal amplitude obtained from the Hall elements to a constant level. If the magnetic field is weak, e.g. with a large vertical gap between magnet and IC, with a weak magnet or at elevated temperatures of the magnet, the AGC value will be high. Likewise, the AGC value will be lower when the magnet is closer to the IC, when strong magnets are used and at low temperatures. www.austriamicrosystems.com/AS5130 Revision 1.12 19 - 41 AS5130 Datasheet - D e t a i l e d D e s c r i p t i o n The best performance of the AS5130 will be achieved when operating within the AGC range. It will still be operational outside the AGC range, but with reduced performance especially with a weak magnetic field due to increased noise. Factors Influencing the AGC Value. In practical use, the AGC value will depend on several factors: The initial strength of the magnet. Aging magnets may show a reducing magnetic field over time which results in an increase of the AGC value. The effect of this phenomenon is relatively small and can easily be compensated by the AGC. al id The vertical distance of the magnet. Depending on the mechanical setup and assembly tolerances, there will always be some variation of the vertical distance between magnet and IC over the lifetime of the application using the AS5130. Again, vertical distance variations can be compensated by the AGC. lv The temperature and material of the magnet. The recommended magnet for the AS5130 is a diametrically magnetized 6mm diameter magnet. Other magnets may also be used as long as they can maintain to operate the AS5130 within the AGC range. Every magnet has a temperature dependence of the magnetic field strength. The temperature coefficient of a magnet depends on the used material. At elevated temperatures, the magnetic field strength of a magnet is reduced, resulting in an increase of the AGC value. At low temperatures, the magnetic field strength is increased, resulting in a decrease of the AGC value. The variation of magnetic field strength over temperature is automatically compensated by the AGC. OTP Sensitivity Adjustment. To obtain best performance and tolerance against temperature or vertical distance fluctuations, the AGC value am lc s on A te G nt st il at normal operating temperature should be in the middle between minimum and maximum, hence it should be around 32 (20H). To facilitate the “vertical centering” of the magnet+IC assembly, the sensitivity of the AS5130 can be adjusted in the OTP register in 8 steps (see Table 10). The OTP sensitivity setting corresponds to the customer register setting gain <2:0>. 7.6 “Pushbutton” Feature Using the magnetic field strength software and hardware indicators described above, the AS5130 provides a useful method of detecting both rotation and vertical distance simultaneously. This is especially useful in applications implementing a rotate-and-push type of human interface (e.g. in panel knobs and switches). The CAO output is low, when the magnetic field is below the low limit (weak or no magnet) and high when the magnetic field is above the low limit (in-range or strong magnet). A finer detection of a vertical distance change, for example when only short vertical strokes are made by the pushbutton, is achieved by memorizing the AGC value in normal operation and triggering on a change from that nominal the AGC value to detect a vertical movement. Figure 15. Magnetic Field Strength Indicator ca +5V VDD VDD CAO Output CS Output DCLK I/O AS5130 AS5130 100n DIO C1 VSS VSS VSS Te ch ni micro controller VDD 1k LED1 www.austriamicrosystems.com/AS5130 Revision 1.12 20 - 41 AS5130 Datasheet - D e t a i l e d D e s c r i p t i o n 7.7 High Speed Operation The AS5130 is using a fast tracking ADC (TADC) to determine the angle of the magnet. The TADC has a tracking rate of 1.15µs (typ). Once the TADC is synchronized with the angle, it sets the LOCK bit in the status register (see Table 9). In worst case, usually at start-up, the TADC requires a maximum of 127 steps (127 * 1.15µS = 146.05µs) to lock. Once it is locked, it requires only one cycle (1.15µs) to track the moving magnet. The AS5130 can operate in locked mode at rotational speeds up to 30,000 rpm. al id In Low Power Mode, the position of the TADC is frozen. It will continue from the frozen position once it is powered up again. If the magnet has moved during the power down phase, several cycles will be required before the TADC is locked again. The tracking time to lock in with the new magnet angle can be roughly calculated as: (EQ 3) 7.7.1 Propagation Delay lv tLOCK = 1.15µs* |NewPos – OldPos| Where: tLOCK = time required to acquire the new angle after power up from one of the reduced power modes [µs] OldPos = Angle position when one of the reduced power modes is activated [º] NewPos = Angle position after resuming from reduced power mode [º] 7.7.2 Sampling Rate am lc s on A te G nt st il The Propagation delay is the time required from reading the magnetic field by the Hall sensors to calculating the angle and making it available on the serial or PWM interface. While the propagation delay is usually negligible on low speeds, it is an important parameter at high speeds. The longer the propagation delay, the larger becomes the angle error for a rotating magnet as the magnet is moving while the angle is calculated. The position error increases linearly with speed. The main factors that contribute to the propagation delay are discussed in detail further in this document. For high speed applications, fast ADCs are essential. The ADC sampling rate directly influences the propagation delay. The fast tracking ADC used in the AS5130 with a tracking rate of only 1.15µs (typ) is a perfect fit for both high speed and high performance. 7.7.3 Chip Internal Lowpass Filtering A commonplace practice for systems using analog-to-digital converters is to filter the input signal by an anti-aliasing filter. The filter characteristic must be chosen carefully to balance propagation delay and noise. The lowpass filter in the AS5130 has a cutoff frequency of typ. 23.8kHz and the overall propagation delay in the analog signal path is typ. 15.6µs. 7.7.4 Digital Readout Rate 7.7.5 ca Aside from the chip-internal propagation delay, the time required to read and process the angle data must also be considered. Due to its nature, a PWM signal is not very usable at high speeds, as you get only one reading per PWM period. Increasing the PWM frequency may improve the situation but causes problems for the receiving controller to resolve the PWM steps. The frequency on the AS5130 PWM output is typ. 1.95kHz with a resolution of 2µs/step. A more suitable approach for high speed absolute angle measurement is using the serial interface. With a clock rate of up to 6MHz, a complete set of data (21bits) can be read in >3.5µs. Total Propagation Delay of the AS5130 ni The total propagation delay of the AS5130 is the delay in the analog signal path and the tracking rate of the ADC: 15.6µs + 1.15µs = 16.75µs (EQ 4) ch If only the SIN-/COS-outputs are used, the propagation delay is the analog signal path delay only (typ. 15.6µs). Position Error Over Speed: The angle error over speed caused by the propagation delay is calculated as: -6 Δθpd = rpm * 6 * 16.75E in degrees (EQ 5) Te In addition, the anti-aliasing filter causes an angle error calculated as: Δθlpf = ArcTan [rpm / (60*f0)] (EQ 6) Table 12. Examples of the Overall Position Error caused by Speed (includes both propagation delay and filter delay) Speed (rpm) Total Position Error (Δθpd + Δθlpf) 100 0.0175º www.austriamicrosystems.com/AS5130 Revision 1.12 21 - 41 AS5130 Datasheet - D e t a i l e d D e s c r i p t i o n Table 12. Examples of the Overall Position Error caused by Speed (includes both propagation delay and filter delay) Speed (rpm) Total Position Error (Δθpd + Δθlpf) 1000 0.175º 10000 1.75º 7.8 Reduced Power Modes lv Low Power Mode: reduced current consumption, very fast start-up. Ideal for short sampling intervals (<3ms). al id The AS5130 can be operated in three reduced power modes. All three modes have in common that they switch off or freeze parts of the chip during intervals between measurements. In Low Power Mode or Ultra Low Power Mode, the AS5130 is not operational, but due to the fast startup, an angle measurement can be accomplished very quickly and the chip can be switched to reduced power immediately after a valid measurement has been taken. Depending on the intervals between measurements, very low average power consumption can be achieved using such a strobed measurement mode. Power Cycling Mode: zero power consumption (externally switched off) during sampling intervals, but slower start-up than Polling Mode. Ideal for sampling intervals 200ms. 7.8.1 Low Power Mode am lc s on A te G nt st il Polling Mode: for reduction of the average power consumption; especially suited for battery powered applications. The AS5130 can be put in Low Power Mode by simple serial commands, using the regular SSI commands. The required serial command is WRITE CONFIG (17H, Figure 4 on page 9). The angle data is valid, as soon as the LOCK- Flag is 1 (see Table 9). In Reduced Power Modes, the AS5130 is inactive. The last state, e.g. the angle, AGC value, etc. is frozen and the chip starts from this frozen state when it resumes active operation. This method provides much faster start-up than a “cold start” from zero. Figure 16. Low Power Mode and Ultra Low Power Mode Connection R1 Ion Ioff VDD ton +5V VDD toff VDD on/off C1 AS5130 S ca 100n N CS DCLK DIO AS5130 VSS C1 micro controller ni VSS Te ch VSS www.austriamicrosystems.com/AS5130 Revision 1.12 22 - 41 AS5130 Datasheet - D e t a i l e d D e s c r i p t i o n If the AS5130 is cycled between active and reduced current mode, a substantial reduction of the average supply current can be achieved. The minimum dwelling time in active mode is the wake-up time. The actual active time depends on how much the magnet has moved while the AS5130 was in reduced power mode. The angle data is valid, when the status bit LOCK has been set (see Table 9). Once a valid angle has been measured, the AS5130 can be put back to reduced power mode. The average power consumption can be calculated as: I active∗ t on + I powerdown∗ t off Iavg = --------------------------------------------------------------------t on + t off sampling interval = ton + toff (EQ 7) al id Where: Iavg = Average current consumption Iactive = Current consumption in active mode Ipower_down = Current consumption in reduced power mode ton = Time period during which the chip is operated in active mode toff = Time period during which the chip is in reduced power mode 7.8.2 am lc s on A te G nt st il lv Reducing Power Supply Peak Currents. An optional RC-filter (Rx/Cx) may be added to avoid peak currents in the power supply line when the AS5130 is toggled between active and reduced power mode. Rx must be chosen such that it can maintain a VDD voltage of 4.5 – 5.5V under all conditions, especially during long active periods when the charge on Cx has expired. Cx should be chosen such that it can support peak currents during the active operation period. For long active periods, Cx should be large and Rx should be small. Power Cycling Mode The power cycling method shown in Figure 17 cycles the AS5130 by switching it on and off, using an external PNP transistor high side switch. The current consumption in off-mode is zero. It also has the longest start-up time of all modes, as the chip must always perform a “cold start“ from zero, which takes about 2ms (Compare with Low Power Mode on page 22). Figure 17. Power Cycling Mode Rx Ion 0 N ca AS5130 S +5V VDD ton toff toff 10k VDD 100n ton Cx >µF CS DCLK DIO AS5130 VSS C1 VDD on/off micro controller ni VSS Te ch VSS The optional filter Rx/Cx may again be added to reduce peak currents in the 5V power supply line (see Reducing Power Supply Peak Currents on page 23). www.austriamicrosystems.com/AS5130 Revision 1.12 23 - 41 AS5130 Datasheet - D e t a i l e d D e s c r i p t i o n 7.8.3 Polling Mode Target of this mode is a reduction of the average power consumption. In this mode, the IC supply is pulsed, thereby reducing the average power consumption to a fraction. The actual angle information and multi turn count value is not lost; polling mode is especially suited for battery powered applications. The IC is furthermore capable of generating a WAKE signal as soon as the magnet’s position has changed, but only if the supply of the IC is powered-on again. By means of the WAKE signal, the system’s power consumption can be further decreased, if certain modules are activated on demand. al id Figure 18. External Circuitry for Polling Mode >1.5K WAKE am lc s on A te G nt st il VSS AS5130 DVDD lv +5V VDD t_wakeup 100n t_off t_on The voltage at pin 16 (DVDD) determines whether polling mode is activated or not. Any voltage above 3.6V activates the polling functionality. This voltage must always be present at DVDD in order to hold the information in the registers. The procedure is as follows: Te ch ni ca 1. Initial startup: The circuit starts up with invalid trim values, which are read back from the storage registers; the command rst_otp (command 19 – 10011) must be sent to read out valid trim values from the OTP. 2. These values are copied to the storage registers if OTP<8> (Wake enable) is set (must be set for polling mode). 3. The values of AGC counter, actual angle, multi turn counter, hysteresis setting, wake threshold and gain setting are continuously updated in the storage registers. 4. The actual angle is stored as a reference by sending command STORE REF (command 3 – 00011). without this reference angle, a WAKE is generated at every startup. 5. The update of the storage registers is stopped if VDD drops below 4.45V and then the information is stored (DVDD) at the next startup (VDD on), the values are read back from the storage registers and the measured angle is compared with the stored reference angle; if the difference between both exceeds the threshold, a WAKE pulse is generated. www.austriamicrosystems.com/AS5130 Revision 1.12 24 - 41 AS5130 Datasheet - D e t a i l e d D e s c r i p t i o n Figure 19. Wake Up Signal Flowchart VDD on (fast) POR store_ok HI reset & reset_storage reset digital core only Retrieve values from storage registers WAKE (26 clk periods) OTP readout (46bit - 140us ... 400us) Compare mode HI | α measured – store_ok ? α stored| > α threshold true false am lc s on A te G nt st il Normal mode lv WAKE_ON LO Wait (162 clks - 86us ... 95us) al id LO Copy to Storage WAKE (20 clk periods) Normal mode command rst_otp true false OTP readout (OTP <8> = HI Figure 21 shows the behavior of the wake up signal. The wake up signal will be low for twakeup = 10us. After that, the wake up signal will go to tristate condition. In case of an angle comparison with a result below the threshold, the signal will remain in tri-state condition. After switching on VDD, the system needs max. 250us to generate an angle with maximum accuracy. A WAKE signal cannot be expected until the end of this period. WAKE Interface. An open drain NMOS structure is used in the WAKE pad. In order to generate a clear output signal level, a pull up resistor is required. The pad can drive 4mA. ca Figure 20. WAKE Output Pin Te ch ni VDD www.austriamicrosystems.com/AS5130 pull up resistor PAD WAKE AS5130 Revision 1.12 25 - 41 AS5130 Datasheet - D e t a i l e d D e s c r i p t i o n Table 13. WAKE Interface Parameters Parameter Min Max Unit Notes Rpull_up Pull up resistor 1.5 100 kΩ The used pad can drive 4mA. twake up Wake up pulse 10 17 µs Interrupt signal to external devices, tri-state output, low active. ton On-time 250 --- µs Time for power up in polling mode. toff Off-time --- --- ms No limit unless DVDD is always supplied. al id Symbol t_off t_on am lc s on A te G nt st il t_on lv Figure 21. Wake Up Signal During Polling Mode of VDD VDD tri-state tri-state WAKE t_wakeup delta (actual - reference angle) </= threshold Te ch ni ca delta (actual - reference angle) > threshold www.austriamicrosystems.com/AS5130 Revision 1.12 26 - 41 AS5130 Datasheet - A p p l i c a t i o n I n f o r m a t i o n 8 Application Information Benefits of AS5130 are as following: Complete system-on-chip Flexible system solution providing absolute angle position, with serial data and PWM output High reliability due to non-contact sensing Robust system, tolerant to misalignment, airgap variations, temperature variations and external magnetic fields 8.1 Application Example I: 3-Wire Sensor with Magnetic Field Strength Indication al id Ideal for applications in harsh environments due to magnetic sensing principle lv In Figure 22, a simple 360º sensor with PWM output is shown. The complete application requires only three wires, VDD, VSS and the PWM output. The circle over the center of the chip represents the diametrically polarized magnet. Additionally, the CAO pin will deliver an analog voltage indicating a missing magnetic field. This signal could be used to drive an external LED or to detect an alert signal. am lc s on A te G nt st il Figure 22. 3-Wire Angle Sensor +5V 1k LED1 VDD PROG CAO 100n AS5130 S AS5130 VSS CAO CS N DCLK PWM PWM out DIO Te ch ni ca VSS www.austriamicrosystems.com/AS5130 Revision 1.12 27 - 41 AS5130 Datasheet - A p p l i c a t i o n I n f o r m a t i o n 8.2 Application Example II: Low-Power Encoder Via SSI, the AS5130 will be able to toggle between active mode and low power mode. In active mode, the current consumption is ~15mA and in low power mode 2mA. The fastest possible startup time from low power mode is 150µs. The AS5130 can be periodically switched between active and low power mode, the average power consumption depends on the duty cycle. In order to read out the correct data, the active mode time must be larger than 150µs. VDD VDD on/off am lc s on A te G nt st il CS lv +5V VDD al id Figure 23. Low Power Encoder 100n AS5130 S N CLK DIO AS5130 VSS micro controller VSS VSS I active∗ t on + I powerdown∗ t off Iavg = --------------------------------------------------------------------t on + t off (EQ 8) Example: sampling period = one measurement every 10ms. ca System constants = Iactive = 15mA, Ipower_down = 2 mA, toff = 9,85ms, ton(min) = 150µs (start-up from low power mode): (EQ 9) Te ch ni 15mA∗ 150μs + 2mA∗ 9, 85ms Iavg = -------------------------------------------------------------------------- = 2.195mA 150μs + 9, 85ms www.austriamicrosystems.com/AS5130 Revision 1.12 28 - 41 AS5130 Datasheet - A p p l i c a t i o n I n f o r m a t i o n 8.3 Application Example III: Polling Mode +5V VDD ton toff +5V DVDD 100n AS5130 S 10k N Cx >1µF CS CLK VDD on/off micro controller DIO am lc s on A te G nt st il AS5130 VSS lv VDD al id Figure 24. Polling Mode VSS VSS Once powered up for at least 2.5ms, the AS5130 can be operated in a pulsed mode, where it is periodically turned on/off by a high side FET (PMOS) switching transistor with a low Ron (<10Ω). The on-time is at least 250µs in order to perform one measurement. A valid measurement result can be verified by checking the lock bit (ADC is locked) in the serial data stream. ca After startup an OTP reset has to be performed in order to read out valid trimming information. Then a special SSI command (STORE REF) copies the actual angle into a buffered reference angle register. Now the AS5130 can be turned off. Special registers will be buffered by the low power supply and will keep the actual settings. After a ton of min. 250 us, the actual angle is compared with the stored reference angle. If the angle difference is larger than a threshold value (wlsb, SSI command WRITE CUST), the AS5130 will send an interrupt request to an external device via the WAKE pin. ni Due to the internal POR level of the IC, ton starts after VDD has reached 4.3V (worst case POR level).The average power consumption in this pulsed mode depends on the supply current in active mode and the duty cycle of the on/off pulse: I active∗ t on Iavg = ------------------------t on + t off (EQ 10) 19mA∗ 250μs Iavg = ------------------------------------------ = 47.5µA 250μs + 99.75ms (EQ 11) Te ch Example: Sampling period = one measurement every 100ms. System constants = Iactive = 19mA, ton(min) = 250µs: www.austriamicrosystems.com/AS5130 Revision 1.12 29 - 41 AS5130 Datasheet - A p p l i c a t i o n I n f o r m a t i o n 8.4 Accuracy of the Encoder System This section enlightens on the individual factors that influence the accuracy of the encoder system, and provides techniques to improve them. Accuracy is defined as the difference between measured angle and actual angle. This is not to be confused with resolution, which is the smallest step that the system can resolve. The two parameters are not necessarily linked together. A high resolution encoder may not necessarily be highly accurate as well. 8.4.1 Quantization Error al id There is however a direct link between resolution and accuracy, which is the quantization error: Quantization Error +1/2 LSB ideal function ideal function digitized function digitized function low resolution high resolution error +1/2 LSB -1/2 LSB ca -1/2 LSB am lc s on A te G nt st il lv Figure 25. Quantization Error of a Low Resolution and a High Resolution System Te ch ni The resolution of the encoder determines the smallest step size. The angle error caused by quantization cannot get better than ± ½ LSB. As shown in Figure 25, a higher resolution system (right picture) has a smaller quantization error, as the step size is smaller. For the AS5130, the quantization error is ± ½ LSB = ± 0.7º www.austriamicrosystems.com/AS5130 Revision 1.12 30 - 41 AS5130 Datasheet - A p p l i c a t i o n I n f o r m a t i o n Figure 26. Typical INL Error over 360º al id INL including quantization error 1,5 1 lv INL [°] 0,5 0 -1 -1,5 0 am lc s on A te G nt st il -0,5 45 90 135 180 225 270 315 360 Angle steps INL Average (16x) Figure 26 shows a typical example of an error curve over a full turn of 360º at a given X-Y- displacement. The curve includes the quantization error, transition noise and the system error. The total error is ~2.2º peak/peak (+/-1.1º). Te ch ni ca The sawtooth-like quantization error (see Figure 25) can be reduced by averaging, provided that the magnet is in constant motion and there are an adequate number of samples available. The solid bold line in Figure 26 shows the moving average of 16 samples. The INL (intrinsic nonlinearity) is reduced to from ~+/- 1.1º down to ~ +/-0.3º. The averaging however, also increases the total propagation delay, therefore it may be considered for low speeds only or adaptive; depending on speed (see Position Error Over Speed: on page 21). www.austriamicrosystems.com/AS5130 Revision 1.12 31 - 41 AS5130 Datasheet - A p p l i c a t i o n I n f o r m a t i o n 8.4.2 Vertical Distance of the Magnet The chip-internal automatic gain control (AGC) regulates the input signal amplitude for the tracking-ADC to a constant value. This improves the accuracy of the encoder and enhances the tolerance for the vertical distance of the magnet. al id Figure 27. Typical Curves for Vertical Distance versus ACG Value on Several Untrimmed Samples 64 2,2 56 lv Linearity and AGC vs Airgap 1,8 40 32 am lc s on A te G nt st il AGC value 48 1,6 24 Linearity [°] 2,0 1,4 16 1,2 8 0 0 500 1000 1500 2000 1,0 2500 Airgap [µm] sample#2 sample#3 sample#4 Linearity [°] ca sample#1 ni As shown in Figure 27, the AGC value (left Y-axis) increases with vertical distance of the magnet. Consequently, it is a good indicator for determining the vertical position of the magnet, for example as a pushbutton feature, as an indicator for a defective magnet or as a preventive warning (e.g. for wear on a ball bearing etc.) when the nominal AGC value drifts away. If the magnet is too close or the magnetic field is too strong, the AGC will be reading 0. If the magnet is too far away (or missing) or if the magnetic field is too weak, the AGC will be reading 63 (3FH). Te ch The AS5130 will still operate outside the AGC range, but the accuracy may be reduced as the signal amplitude can no longer be kept at a constant level. The linearity curve in Figure 27 (right Y-axis) shows that the accuracy of the AS5130 is best within the AGC range, even slightly better at small airgaps (0.4 – 0.8mm). At very short distances (0 – 0.1) the accuracy is reduced, mainly due to nonlinearities in the magnetic field. At larger distances, outside the AGC range (~2.0 – 2.5mm and more) the accuracy is still very good, only slightly decreased from the nominal accuracy. Since the field strength of a magnet changes with temperature, the AGC will also change when the temperature of the magnet changes. At low temperatures, the magnetic field will be stronger and the AGC value will decrease. At elevated temperatures, the magnetic field will be weaker and the AGC value will increase. www.austriamicrosystems.com/AS5130 Revision 1.12 32 - 41 AS5130 Datasheet - A p p l i c a t i o n I n f o r m a t i o n 8.4.3 Choosing the Proper Magnet There is no strict requirement on the type or shape of the magnet to be used with the AS5130. It can be cylindrical as well as square in shape. The key parameter is that the vertical magnetic field Bz measured at a radius of 1mm from the rotation axis is sinusoidal with a peak amplitude of 20...80mT (see Figure 28). S am lc s on A te G nt st il N lv typ. 6mm diameter al id Figure 28. Vertical Magnetic Fields of a Rotating Magnet Magnet axis Magnet axis R1 Vertical field component N S R1 concentric circle; radius 1.0 mm Vertical field component Bz (20…80mT) 0 360 Te ch ni ca 360 www.austriamicrosystems.com/AS5130 Revision 1.12 33 - 41 AS5130 Datasheet - A p p l i c a t i o n I n f o r m a t i o n 8.4.4 Magnet Placement al id Ideally, the center of the magnet, the diagonal center of the IC and the rotation axis of the magnet should be in one vertical line. The lateral displacement of the magnet should be within ±0.25mm from the IC package center or +/-0.5mm from the IC center, including the placement of the chip within the IC package. The vertical distance should be chosen such that the magnetic field on the die surface is within the specified limits. The typical distance “z” between the magnet and the package surface is 0.5mm to 1.8mm with the recommended magnet (6mm x 2.5mm). Larger gaps are possible, as long as the required magnetic field strength stays within the defined limits. A magnetic field outside the specified range may still produce acceptable results, but with reduced accuracy. The out-of-range condition will be indicated, when the AGC is at the limits (AGC= 0: field too strong; AGC=63=(3FH): field too weak or missing magnet). lv Figure 29. Bz Field Distribution Along the X-axis of a 6mmØ Diametric Magnetized Magnet Bz; 6mm magnet @y=0; z=1mm 0.0015 S am lc s on A te G nt st il N 0.001 0.0005 0 -0.0005 -0.001 -0.0015 3.5 2.5 1.5 0.5 -0.5 -1.5 -2.5 -3.5 ca X-displacement [mm] ch ni Figure 29 shows a cross sectional view of the vertical magnetic field component Bz between the north and south pole of a 6mm diameter magnet, measured at a vertical distance of 1mm. The poles of the magnet (maximum level) are about 2.8mm from the magnet center, which is almost at the outer magnet edges. The magnetic field reaches a peak amplitude of ~±106mT at the poles. The Hall elements are located at a radius of 1mm (indicated as squares at the bottom of the graph). Due to the side view, the two Hall elements at the Y-axis are overlapping at X=0mm, therefore only 3 Hall elements are shown. At 1mm radius, the peak amplitude is ~±46mT, respectively a differential amplitude of 92mT. The vertical magnetic field Bz follows a fairly linear pattern up to about 1.5mm radius. Consequently, even if the magnet is not perfectly centered, the differential amplitude will be the same as for a centered magnet. Te For example, if the magnet is misaligned in X-axis by -0.5mm, the two X-Hall sensors will measure 70mT (@ x = -1.5mm) and -22mt (@ x = 0.5mm). Again, the differential amplitude is 92mT. At larger displacements however, the Bz amplitude becomes nonlinear, which results in larger errors that mainly affect the accuracy of the system (see Figure 31). www.austriamicrosystems.com/AS5130 Revision 1.12 34 - 41 AS5130 Datasheet - A p p l i c a t i o n I n f o r m a t i o n Figure 30. Vertical Magnetic Field Distribution of a Cylindrical 6mmØ Diametric Magnetized Magnet at 1mm Gap area of X-Y-misalignment from center: +/- 0.5mm N 125 circle of Hall elements on chip: 1mm radius lv 100 75 50 25 0 -25 -50 -75 -100 -125 am lc s on A te G nt st il Bz [mT] al id BZ; 6mm magnet @ Z=1mm 4 3 2 4 S 3 2 1 0 -1 2 -2 1 0 X-displacement [mm] -3 -1 Y-displacement [mm] -4 -2 -3 8.4.5 ca Figure 30 shows the same vertical field component as Figure 29, but in a 3-dimensional view over an area of ±4mm from the rotational axis. Lateral Displacement of the Magnet ni As shown in the magnet specifications (see Parameters for Magnet under Electrical Characteristics on page 6), the recommended horizontal position of the magnet axis with respect to the IC package center is within a circle of 0.25mm radius. This includes the placement tolerance of the IC within the package. Te ch Figure 31 shows a typical error curve at a medium vertical distance of the magnet around 1.2mm (AGC = 24). The X- and Y- axis of the graph indicate the lateral displacement of the magnet center with respect to the IC center. At X=Y=0, the magnet is perfectly centered over the IC. The total displacement plotted on the graph is for ±1mm in both directions. The Z-axis displays the worst case INL error over a full turn at each given X-and Y- displacement. The error includes the quantization error of ±0.7º (refer to Quantization Error on page 30). For example, the accuracy for a centered magnet is between 1.0 – 1.5º (spec = 2º over full temperature range). Within a radius of 0.5mm, the accuracy is better than 2.0º (spec = 3º over temperature). www.austriamicrosystems.com/AS5130 Revision 1.12 35 - 41 AS5130 Datasheet - A p p l i c a t i o n I n f o r m a t i o n Figure 31. Typical Error Curve of INL Error Over Lateral Displacement (including quantization error) al id INL vs. Displacement: AS5030 for AGC24 lv 4,500-5,000 4,000-4,500 5,000 3,500-4,000 4,500 am lc s on A te G nt st il 3,000-3,500 4,000 3,500 3,000 2,500 INL [°] 2,000 1,500 1,000 0,500 0,000 2,500-3,000 1000 750 500 250 2,000-2,500 1,500-2,000 1,000-1,500 0,500-1,000 0,000-0,500 0 -1000 -750 -250 -500 -500 -250 0 250 X Displacem ent [µm ] Y Displacem ent [µm ] -750 500 -1000 750 8.4.6 Magnet Size ca 1000 Figure 29 to Figure 31 illustrate a cylindrical magnet with a diameter of 6mm. Smaller magnets may also be used, but since the poles are closer together, the linear range will also be smaller and consequently the tolerance for lateral misalignment will also be smaller. ch ni If the ±0.25mm lateral misalignment radius (rotation axis to IC package center) is too tight, a larger magnet can be used. Larger magnets have a larger linear range and allow more misalignment. However at the same time the slope of the magnet is more flat, which results in a lower differential amplitude. This requires either a stronger magnet or a smaller gap between IC and magnet in order to operate in the amplitudecontrolled area (AGC > 0 and AGC < 63). In any case, if a magnet other than the recommended 6mm diameter magnet is used, two parameters should be verified: Te Verify, that the magnetic field produces a sinusoidal wave, when the magnet is rotated. Note that this can be done with the SIN-/COS- outputs of the AS5130; e.g. rotate the magnet at constant speed and analyze the SIN- (or COS-) output with an FFT-analyzer. It is recommended to disable the AGC for this test (see Analog Sin/Cos Outputs with External Interpolator on page 13). Verify that the Bz-Curve between the poles is as linear as possible (see Figure 29). This curve may be available from the magnet supplier(s). Alternatively, the SIN- or COS- output of the AS5130 may also be used together with an X-Y- table to get a Bz-scan of the magnet (as in Figure 29 or Figure 30). Furthermore, the sinewave tests described above may be re-run at defined X-and Y- misplacements of the magnet to determine the maximum acceptable lateral displacement range. It is recommended to disable the AGC for both these tests (see Analog Sin/Cos Outputs with External Interpolator on page 13). Note: For preferred magnet suppliers, please refer to the austriamicrosystems website (Rotary Encoder section). www.austriamicrosystems.com/AS5130 Revision 1.12 36 - 41 AS5130 Datasheet - P a c k a g e D r a w i n g s a n d M a r k i n g s 9 Package Drawings and Markings The device is available in a 16-Lead Shrink Small Outline Package. Figure 32. Package Drawings and Dimensions YYWWMZZ Te ch ni ca 513001 Max 1.99 0.21 1.78 0.38 0.25 6.50 8.20 5.60 0.95 8º al id Nom 1.86 0.13 1.73 0.30 0.17 6.20 7.80 5.30 0.65 BSC 0.75 1.25 REF 0.25 BSC 4º 16 lv Min 1.73 0.05 1.68 0.22 0.09 5.90 7.40 5.00 0.55 0.09 0º am lc s on A te G nt st il Symbol A A1 A2 b c D E E1 e L L1 L2 R Θ N www.austriamicrosystems.com/AS5130 Revision 1.12 37 - 41 AS5130 Datasheet - P a c k a g e D r a w i n g s a n d M a r k i n g s Notes: 1. Dimensions and tolerancing conform to ASME Y14.5M-1994. 2. All dimensions are in millimeters, angle are in degrees. Marking: YYWWMZZ. WW M ZZ Year Manufacturing Week Assembly plant identifier Assembly traceability code 9.1 Recommended PCB Footprint am lc s on A te G nt st il lv Figure 33. PCB Footprint al id YY Te ch ni ca Recommended Footprint Data Symbol mm inch A 9.02 0.355 B 6.16 0.242 C 0.46 0.018 D 0.65 0.025 E 5.01 0.197 www.austriamicrosystems.com/AS5130 Revision 1.12 38 - 41 AS5130 Datasheet - R e v i s i o n H i s t o r y Revision History Revision Date Owner Description 1.5 May 31, 2007 Initial version 1.6 Sep 11, 2008 Ordering code updated 1.9 Mar 03, 2009 Updated Absolute Maximum Ratings (page 5) 1.11 Jun 09, 2010 1) Replaced instances of ‘sleep mode’ to ‘low power mode’ 2) Removed duplicate instances of TpwrUp and N; Deleted Hyst from Table 6. 3) Replaced instances of AVDD to VDD 4) Updated diagram for Extended Operation Mode (for access of OTP only) (page 10) 1.12 May 12, 2011 lv rfu am lc s on A te G nt st il 1.10 al id Feb 02, 2010 Updated values for the following parameters (see Electrical Characteristics on page 6) 1) Power Supply Current 2) PWM Period 3) PWM Frequency apg mub Updated Absolute Maximum Ratings, Electrical Characteristics, Package Drawings and Markings. Te ch ni ca Note: Typos may not be explicitly mentioned under revision history. www.austriamicrosystems.com/AS5130 Revision 1.12 39 - 41 AS5130 Datasheet - O r d e r i n g I n f o r m a t i o n 10 Ordering Information The devices are available as the standard products shown in Table 14. Table 14. Ordering Information Delivery Form 8-bit Magnetic Rotary Encoder with Multiturn function Tape & Reel Tubes Package 16-pin SSOP (5.3mm x 6.2mm) Note: All products are RoHS compliant and austriamicrosystems green. Buy our products or get free samples online at ICdirect: http://www.austriamicrosystems.com/ICdirect Technical Support is available at http://www.austriamicrosystems.com/Technical-Support Te ch ni ca am lc s on A te G nt st il For further information and requests, please contact us mailto: [email protected] or find your local distributor at http://www.austriamicrosystems.com/distributor al id AS5130-ASST-OM AS5130-ASSU-OM Description lv Ordering Code www.austriamicrosystems.com/AS5130 Revision 1.12 40 - 41 AS5130 Datasheet - C o p y r i g h t s Copyrights Copyright © 1997-2011, austriamicrosystems AG, Tobelbaderstrasse 30, 8141 Unterpremstaetten, Austria-Europe. Trademarks Registered ®. All rights reserved. The material herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. All products and companies mentioned are trademarks or registered trademarks of their respective companies. al id Disclaimer lv Devices sold by austriamicrosystems AG are covered by the warranty and patent indemnification provisions appearing in its Term of Sale. austriamicrosystems AG makes no warranty, express, statutory, implied, or by description regarding the information set forth herein or regarding the freedom of the described devices from patent infringement. austriamicrosystems AG reserves the right to change specifications and prices at any time and without notice. Therefore, prior to designing this product into a system, it is necessary to check with austriamicrosystems AG for current information. This product is intended for use in normal commercial applications. Applications requiring extended temperature range, unusual environmental requirements, or high reliability applications, such as military, medical life-support or life-sustaining equipment are specifically not recommended without additional processing by austriamicrosystems AG for each application. For shipments of less than 100 parts the manufacturing flow might show deviations from the standard production flow, such as test flow or test location. Contact Information ca Headquarters am lc s on A te G nt st il The information furnished here by austriamicrosystems AG is believed to be correct and accurate. However, austriamicrosystems AG shall not be liable to recipient or any third party for any damages, including but not limited to personal injury, property damage, loss of profits, loss of use, interruption of business or indirect, special, incidental or consequential damages, of any kind, in connection with or arising out of the furnishing, performance or use of the technical data herein. No obligation or liability to recipient or any third party shall arise or flow out of austriamicrosystems AG rendering of technical or other services. ni austriamicrosystems AG Tobelbaderstrasse 30 A-8141 Unterpremstaetten, Austria ch Tel: +43 (0) 3136 500 0 Fax: +43 (0) 3136 525 01 For Sales Offices, Distributors and Representatives, please visit: Te http://www.austriamicrosystems.com/contact www.austriamicrosystems.com/AS5130 Revision 1.12 41 - 41