MA704 MPS | Alldatasheet
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10-Bit, Digital, Contactless Angle Sensor with ABZ Incremental & PWM Outputs MA704 Rev. 1.0 www.MonolithicPower.com 1 9/27/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved.
DESCRIPTION
The MA704 detects the absolute angular position of a permanent magnet, typically a diametrically magnetized cylinder on a rotating shaft. The MA704 is particularly suited to track highly dynamic movements with speeds up to 60’000 rpm. The MA704 supports a wide range of m agnetic field strengths and spat ial configurations. Both end-of-shaft and off -axis (side-shaft mounting) configurations are supported. The MA704 features magnetic field strength detection with programmable thresholds to allow sensing of the magnet position relative to the sensor for creation of functions such a s the sensing of axial movements or for diagnostics. On-chip non-volatile memory provides storage for configuration parameters, including the reference zero angle position , ABZ encoder settings, and magnetic field detection thresholds.
FEATURES
10-Bit Resolution Absolute Angle Encoder Contactless Sensing for Long Life SPI Serial Interface for Digital Angle Readout and Chip Configuration Incremental 8-Bit ABZ Quadrature Encoder Interface with Programmable Pulses Per Turn from 1-64 PWM Output 10-Bit Programmable Magnetic Field Strength Detection for Diagnostic Checks 3.3V, 12 mA Supply -40°C to +125°C Operating Temperature Available in a QFN-16 (3mmx3mm) Package
APPLICATIONS
General Purpose Angle Measurement Angle Encoders Automotive Angle or Speed Sensors Robotics All MPS parts are lead-free, halogen-free, and adhere to the RoHS directive. For MPS green status, please visit the MPS website under Quality Assurance. “MPS” and “The Future of Analog IC Technology” are registered trademarks of Monolithic Power Systems, Inc. TYPICAL APPLICATION
MA704 – 10-BIT, DIGITAL ANGLE SENSOR WITH ABZ & UVW OUTPUTS MA704 Rev. 1.0 www.MonolithicPower.com 2 9/27/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved.
ORDERING INFORMATION
Part Number* Package Top Marking MA704GQ QFN-16 (3mmx3mm) See Below * For Tape & Reel, add suffix –Z (e.g. MA704GQ–Z) TOP MARKING BAN: Product code of MA704GQ Y: Year code LLL: Lot number PACKAGE REFERENCE TOP VIEW QFN-16 (3mmx3mm)
MA704 – 10-BIT, DIGITAL ANGLE SENSOR WITH ABZ & UVW OUTPUTS MA704 Rev. 1.0 www.MonolithicPower.com 3 9/27/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. ABSOLUTE MAXIMUM RATINGS (1) Continuous power dissipation (TA = +25°C) (2) Thermal Resistance (3) θJA θJC NOTES: 1) Exceeding these ratings may damage the device. 2) The maximum allowable power dissipation is a function of the maximum junction temperature T J (MAX), the junction -to- ambient thermal resistance θ JA, and the ambient temperature TA. The maximum allowable continuous power dissipation at any ambient temperature is calculated by P D (MAX) = (T J (MAX)-TA)/θJA. 3) Measured on JESD51-7, 4-layer PCB.
MA704 – 10-BIT, DIGITAL ANGLE SENSOR WITH ABZ & UVW OUTPUTS MA704 Rev. 1.0 www.MonolithicPower.com 4 9/27/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved.
ELECTRICAL CHARACTERISTICS
Parameter Symbol Condition Min Typ Max Units Recommended Operating Conditions Supply voltage VDD 3.0 3.3 3.6 V Supply current IDD From -40°C to +125°C 10.2 11.7 13.8 mA Operating temperature Top -40 125 °C Applied magnetic field B 30 60 mT
MA704 – 10-BIT, DIGITAL ANGLE SENSOR WITH ABZ & UVW OUTPUTS MA704 Rev. 1.0 www.MonolithicPower.com 5 9/27/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. GENERAL CHARACTERISTICS VDD = 3.3V, 45mT < B < 100mT, Temp = -40°C to +125°C, unless otherwise noted. Parameter Symbol Condition Min Typ Max Units Absolute Output – Serial Effective resolution 3σ deviation of the noise distribution 9.5 10.0 10.5 bit Noise RMS 0.04 0.06 0.08 deg Refresh rate 850 980 1100 kHz Data output length 12 12 bit Response Time Power-up time (4) 1.1 ms Latency (4) Constant speed propagation delay 8 10 µs Filter cutoff frequency (4) Fcutoff 2970 Hz Accuracy INL at 25°C At room temperature over the full field range 0.7 deg INL between -40°C to +125°C (5) Over the full temperature range and field range 1.1 deg Output Drift Temperature induced drift at room temperature (5) 0.015 0.04 deg/°C Temperature induced variation (5) From 25°C to 85°C 0.5 1.2 deg From 25°C to 125°C 1.0 2.1 deg Magnetic field induced (5) 0.005 deg/mT Voltage supply induced (5) 0.3 deg/V Absolute Output – PWM PWM frequency 782 920 1010 Hz PWM resolution 9.5 10.0 bit Incremental Output – ABZ ABZ update rate 16 MHz Resolution - edges per turn Programmable 4 256 Pulses per channel per turn PPT+1 Programmable 1 64 ABZ hysteresis (5) H 1.1 deg Systematic jitter (5) For PPT = 63, 0 - 100kRPM 6.0 % Random jitter (3σ) For PPT = 63, 0 - 100kRPM 3.0 % Overall ABZ jitter (5) 0.5 deg
MA704 – 10-BIT, DIGITAL ANGLE SENSOR WITH ABZ & UVW OUTPUTS MA704 Rev. 1.0 www.MonolithicPower.com 6 9/27/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. GENERAL CHARACTERISTICS (continued) VDD = 3.3V, 45mT < B < 100mT, Temp = -40°C to +125°C, unless otherwise noted. Parameter Symbol Condition Min Typ Max Units Magnetic Field Detection Thresholds Accuracy (5) 5 mT Hysteresis (5) MagHys 6 mT Temperature drift (5) -600 ppm/°C Digital I/O Input high voltage VIH 2.5 5.5 V Input low voltage VIL -0.3 0.8 V Output low voltage (5) VOL IOL = 4mA 0.4 V Output high voltage (5) VOH IOH = 4mA 2.4 V Pull-down resistor RPD 43 55 97 kΩ Rising edge slew rate(4) TR CL = 50pF 0.7 V/ns Falling edge slew rate (4) TF CL = 50pF 0.7 V/ns NOTES: 4) Guaranteed by design. 5) Guaranteed by characteristic test.
MA704 – 10-BIT, DIGITAL ANGLE SENSOR WITH ABZ & UVW OUTPUTS MA704 Rev. 1.0 www.MonolithicPower.com 7 9/27/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. TYPICAL CHARACTERISTICS VDD = 3.3V, Temp = 25°C, unless otherwise noted. ABZ Jitter at PPT = 255 Noise Spectrum at 50mT Filter Transfer Function 1.5 2.5 0.1 1 10 100 1000 104 105 RANDOM JITTER (%) ROTATION SPEED (rpm) 0.001 0.01 10 100 1000 104 105 NOISE DENSITY (deg/Hz FREQUENCY (Hz) -20 -15 -10 10 100 1000 104 105 FILTER TRANSFER FUNCTION (dB) f (Hz) -3 dB Error Curves at 50mT Non-Linearity (INL and Harmonics) Effective Resolution (3σ) 0 50 100 150 200 250 300 350 ERROR (deg) ANGLE (deg) 125°C -45°C 25°C 0 20 40 60 80 100 120 EFFECTIVE RESOLUTION (bit) MAGNETIC FIELD (mT) Current Consumption at VDD = 3.3V 0.5 1.5 0 20 40 60 80 100 NON-LINEARITY (deg) MAGNETIC FIELD (T) INL 10.5 11.5 -50 0 50 100 150 SUPPLY CURRENT (mA) TEMPERATURE (°C)
MA704 – 10-BIT, DIGITAL ANGLE SENSOR WITH ABZ & UVW OUTPUTS MA704 Rev. 1.0 www.MonolithicPower.com 8 9/27/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. PIN FUNCTIONS Package Pin # Name Description 1 SSD Data out (SSI). 2 A Incremental output. 3 Z Incremental output. 4 MOSI Data in (SPI). MOSI has an internal pull-down resistor. 5 CS Chip select (SPI). CS has an internal pull-up resistor. 6 B Incremental output. 7 MISO Data out (SPI). MISO has an internal pull-down resistor that is enabled at a high impedance state. 8 GND Supply ground. 9 PWM PWM output. 10 TEST Connect to ground. 11 MGL Digital output indicating field strength below MGLT level. 12 SCLK Clock (SPI). SCLK has an internal pull-down resistor. 13 VDD Supply 3.3V. 14 NC No connection. Leave NC unconnected. 15 SSCK Clock (SSI). SSCK has an internal pull-down resistor. 16 MGH Digital output indicating field strength above MGHT level.
MA704 – 10-BIT, DIGITAL ANGLE SENSOR WITH ABZ & UVW OUTPUTS MA704 Rev. 1.0 www.MonolithicPower.com 9 9/27/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. BLOCK DIAGRAM Figure 1: Functional Block Diagram Phase detection Digital conditioning Serial interface MISO CS SCLK MA704 Spinaxis front-end BP 2D Hall effect device VDD GND SSCK SSD Registers Amplitude detection MGL MGH NVM MOSI ABZ encoder A B Z PWMPWM
MA704 – 10-BIT, DIGITAL ANGLE SENSOR WITH ABZ & UVW OUTPUTS MA704 Rev. 1.0 www.MonolithicPower.com 15 9/27/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. SPI Write Register Table 7 shows the programmable 8-bit registers. Data written to these registers are stored in the on-chip n on-volatile memory and reloaded at power-on automatically. The factory default register values are shown in Table 8. A write register operation is constituted of two 16-bit frames. The first frame sends a write request, which contains the 3-bit write command (100) followed by the 5 -bit register address and the 8 -bit value (MSB first). The second frame returns the newly written register value (acknowledge). The on -chip memory is guaranteed to endure 1,000 write cycles at 25°C. It is critical to wait 20ms between the first and the second frame. This is the time taken to write the non-volatile memory. Failure to implement this wait period result s in the register ’s previous value being read . Note that this delay is only required after a write request. A read register request and read angle do not require this wait time. First 16-bit SPI frame (write request): MSB LSB MISO Angle(15:0) command reg. address reg. value MOSI 1 0 0 A4 A3 A2 A1 A0 V7 V6 V5 V4 V3 V2 V1 V0 Second 16-bit SPI frame (response): reg. value MISO V7 V6 V5 V4 V3 V2 V1 V0 0 0 0 0 0 0 0 0 MSB LSB MOSI 0 The read back register content can be used to verify the register programming. See Figure 13 for a complete transmission overview. For example, to set the value of the output rotation direction (RD) to counterclockwise (high). Write register 9 by sending the following first frame: MSB LSB MISO Angle(15:0) command reg. address reg. value MOSI 1 0 0 0 1 0 0 1 1 0 0 0 0 0 0 0 Send the second frame after a 20ms wait time. If the register is written correctly, the reply is: reg. value MISO 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 MSB LSB MOSI 0 See Figure 14 for a complete example. Figure 13: Overview of Two 16-Bit Frames Write Register Operation
MA704 – 10-BIT, DIGITAL ANGLE SENSOR WITH ABZ & UVW OUTPUTS MA704 Rev. 1.0 www.MonolithicPower.com 18 9/27/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. REGISTER MAP Table 7: Register Map No Hex Bin Bit 7 MSB Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 LSB 0 0x0 00000 Z(7:0) 1 0x1 00001 Z(15:8) 2 0x2 00010 BCT(7:0) 3 0x3 00011 - - - - - - ETY ETX 4 0x4 00100 PPT(1:0) ILIP(3:0) - - 5 0x5 00101 - - - - PPT(5:2) 6 0x6 00110 MGLT(2:0) MGHT(2:0) - - 9 0x9 01001 RD - - - - - - - 27 0x1B 11011 MGH MGL - - - - - - Table 8: Factory Default Values No Hex Bin Bit 7 MSB Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 LSB 0 0x0 00000 0 0 0 0 0 0 0 0 1 0x1 00001 0 0 0 0 0 0 0 0 2 0x2 00010 0 0 0 0 0 0 0 0 3 0x3 00011 0 0 0 0 0 0 0 0 4 0x4 00100 1 1 0 0 0 0 0 0 5 0x5 00101 0 0 0 0 1 1 1 1 6 0x6 00110 0 0 0 1 1 1 0 0 9 0x9 01001 0 0 0 0 0 0 0 0 Table 9: Programming Parameters Parameters Symbol Number of Bits Description See Table Zero Setting Z 16 Set the zero position 10 Bias Current Trimming BCT 8 For side-shaft configuration: reduce the bias current of the X or Y Hall device 13 Enable Trimming X ETX 1 Biased current trimmed in the X direction Hall device 14 Enable Trimming Y ETY 1 Biased current trimmed in the Y direction Hall device 14 Pulses Per Turn PPT 6 Number of pulses per turn of the ABZ output 17 Index Length / Index Position ILIP 4 Parametrization of the ABZ index pulse Fig 26 Magnetic Field High Threshold MGHT 3 Sets the field strength high threshold 16 Magnetic Field Low Threshold MGLT 3 Sets the field strength low threshold 16 Rotation Direction RD 1 Determines the sensor positive direction 12
MA704 – 10-BIT, DIGITAL ANGLE SENSOR WITH ABZ & UVW OUTPUTS MA704 Rev. 1.0 www.MonolithicPower.com 19 9/27/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. REGISTER SETTINGS Zero Setting The zero position of the MagAlpha ( a0) can be programmed with 16 bits of resolution. The angle streamed out by the MagAlpha (aout) is given by Equation (2): 0aaa rawout (2) Where araw is the raw angle provided by the MagAlpha front end. The parameter Z(15:0), which is zero by default, is the complementary angle of the zero setting . In decimals, it can be written as shown in Equation (3): )0:15(216
0 Za (3)
Table 10 shows the zero setting parameter. Table 10: Zero Setting Parameter Z(15:0) Zero pos. a0 (16-bit dec) Zero pos. a0 (deg) 0 65536 360.000 1 65535 359.995 2 65534 359.989 … … … 65534 2 0.011 65535 1 0.005 Example To set the zero position to 20 degrees, the Z(15:0) parameter shall be equal to the complementary angle and can be calculated with Equation (4): 618952deg360 In binary, it is written as 1111 0001 1100 0111. Table 11 shows the content of the registers 0 and Table 11: Register 0 and 1 Content Reg Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 0 1 1 0 0 0 1 1 1 1 1 1 1 1 0 0 0 1 Rotation Direction By default , when looking at the top of the package, the angle increases when the magnetic field rotates clockwise (CW) (see Figure 18 and Table 12). Figure 18: Positive Rotation Direction of the Magnetic Field Table 12: Rotation Direction Parameter RD Positive Direction
0 Clockwise (CW)
1 Counterclockwise (CCW)
BCT Settings (Bias Current Trimming) Side Shaft When the MA704 is mounted on the side of the magnet, the relation between the field angle and the mechanical angle is no longer directly linear. This effect is related to the fact that the tangential magnetic field is usually smaller than the radial field. Define the field ratio k with Equation (5): tan/ BBk rad (5) Where Brad and Btan are the maximum radial and tangential magnetic fields (see Figure 19). Figure 19: Side-Shaft Field The ratio k depends on the magnet geometry and the distance to the sensor. Having a k ratio different than 1 results in the sensor output response not being linear with respect to the mechanical angle. Note that the error curve has the shape of a double sinewave (see Figure 21). E is the amplitude of this error.
MA704 – 10-BIT, DIGITAL ANGLE SENSOR WITH ABZ & UVW OUTPUTS MA704 Rev. 1.0 www.MonolithicPower.com 21 9/27/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. Figure 22: Relation between the Error Measured with BCT = 0 and the Magnet Ratio k Sensor Orientation From the dot marked on the package , it is possible to know whether the radial field is aligned with the sensor coordinate X or Y (see Figure 23). Figure 23: Package Top View with X and Y Axes Determine which axis needs to be reduced (see the qualitative field distribution around a ring in Figure 19). For instance, with the arrangement depicted in Figure 23, the field along the sensor Y direction is tangential and weaker. The X-axis should be reduced (ETX = 1 and ETY = 0). Note that if both ETX and ETY are set to 1, the current bias is reduced in both directions the same way (i.e.: without side -shaft correcti on) (see Table 14). Table 14: Trimming Direction Parameters ETX Enable Trimming of the X-Axis
0 Disabled
1 Enabled
ETY Enable Trimming of the Y-Axis The magnetic flags (MGL and MGH ) indicate that the magnetic field at the sen sor position is out a range defined by t he lower (MGLT) and upper magnetic field thresholds (MGHT) (see Figure 24). Figure 24: MGH and MGL Signals as a Function of the Field Strength MagHys, the typical hysteresis on the signals MGH and MGL is 6mT. The MGLT and MGHT thresholds are coded on three bits and stored in register 6 (see Table 15). Table 15: Register 6 Register 6 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 MGLT MGHT - - The 3-bit values of MGLT and MGHT correspond to the magnetic field (see Table 16). Table 16: MGLT and MGHT: Binary to mT Relation MGLT or MGHT (8) Field threshold in mT (7) From low to high magnetic field From high to low magnetic field 000 26 20 001 41 35 010 56 50 011 70 64 100 84 78 101 98 92 110 112 106 111 126 120 NOTES: 7) Valid for VDD=3.3V. If different then field threshold is scaled by the factor VDD/3.3V. 8) MGLT can have a larger value than MGHT. The alarm flags MGL and MGH are available to be read in register 27 (bit 6, bit 7), and their logic state is also given at the digital output pin s 11 and 16. 1.5 2.5 3.5 4.5 0 5 10 15 20 25 30 35 40 k E (deg)
MA704 – 10-BIT, DIGITAL ANGLE SENSOR WITH ABZ & UVW OUTPUTS MA704 Rev. 1.0 www.MonolithicPower.com 25 9/27/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved.
PACKAGE INFORMATION
QFN-16 (3mmx3mm)
MA704 – 10-BIT, DIGITAL ANGLE SENSOR WITH ABZ & UVW OUTPUTS MA704 Rev. 1.0 www.MonolithicPower.com 26 9/27/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. APPENDIX A: DEFINITIONS Effective Resolution (3σ noise level) This is the smallest angle increment distinguishable from the noise. The resolution is measured by computing three times σ ( the standard deviation in degrees) taken over 1,000 data points at a constant position. The resolution in bits is obtained with: log2(360/6σ). Refresh Rate Rate at which new data points are stored in the output buffer. ABZ Update Rate Rate at which a new ABZ s tate is computed. The inverse of this ra te is the minimum time between two ABZ edges. Latency The time elapsed between the instant when the data is ready to be read and the instant at which the shaft passes that position. The lag in degrees is , where 𝑣 is the angular velocity in deg/s. Power-Up Time Time until the sensor delivers valid data starting at power up. Integral Non -Linearity (INL) Maximum deviation between the average sensor output (at a fixed position) and the true mechanical angle. Figure A1: Resolution, INL, Lag INL can be obtained from the error curve , where is the average over 1000 sensor output and is the mechanical angle indicated by a high precision encoder (<0.001 deg). INL is then computed with Equation (A1): ))(min())(max( aerraerrINL (A1) Drift Angle variation rate when one parameter is changed (e.g.: temperature, VDD) and all the others, including the shaft angle, are maintained constant. 100 150 200 250 300 350 400 0 100 200 300 400 500 600 700 sensor out (deg) rotor position (deg) resolution ( ± 3 ) ideal sensor output INL lag sensor out best straight fit
MA704 – 10-BIT, DIGITAL ANGLE SENSOR WITH ABZ & UVW OUTPUTS NOTICE: The information in this document is subject to change without notice. Users should warrant and guarantee that third party Intellectual Property rights are not infringed upon when integrating MPS products into any application. MPS will not assume any legal responsibility for any said applications. MA704 Rev. 1.0 www.MonolithicPower.com 27 9/27/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. APPENDIX B: SPI COMMUNICATION CHEATSHEET Read Angle Read Register Write Register