MP20073DH-LF-P

MagAlpha MA120 R EC N R E OM EF W M ER D E ES N TO IG DE M NS D F A1 O R 02 Angular Sensor for Brushless Motor Commutation DESCRIPTION FEATURES The MagAlpha MA120 magnetic sensor is an allin-one solution designed to replace Hall switches for 3-phase block commutation in brushless DC motors. The MA120 detects the absolute angular position of a permanent magnet, typically a diametrically magnetized cylinder attached to the rotor. The data acquisition and processing is extremely fast, allowing for accurate angle measurement at speeds from 0 to 120,000 RPM.        The MA120 supports a wide magnetic field strength range, which helps relax mechanical tolerances and simplify system design.  UVW Signals for Block Commutation 11-Bit Resolution Absolute Angle Encoder 500kHz Refresh Rate Ultra-Low Latency: 3µs SPI Serial Interface 3.3V, 7.7mA Supply Available in a QFN-16 (3mmx3mm) Package APPLICATIONS PSM/BLDC Motors 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. Please See Position Sensor Design Support for All Supporting Software N O T TYPICAL APPLICATION MA120 Rev. 1.2 7/3/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 1 MA120 – ANGULAR SENSOR FOR BRUSHLESS MOTOR COMMUTATION ORDERING INFORMATION Package Top Marking See Below R EC N R E OM EF W M ER D E ES N TO IG DE M NS D F A1 O R 02 Part Number* MA120GQ QFN-16 (3mmx3mm) * For Tape & Reel, add suffix –Z (e.g. MA120GQ–Z) TOP MARKING y: Year code O: Optional marking LLL: Lot number PACKAGE REFERENCE N O T TOP VIEW QFN-16 (3mmx3mm) MA120 Rev. 1.2 7/3/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 2 MA120 – ANGULAR SENSOR FOR BRUSHLESS MOTOR COMMUTATION ABSOLUTE MAXIMUM RATINGS (1) Thermal Resistance Supply voltage (continuous) ........ -0.5V to +3.8V Supply voltage short term ........... -0.5V to +4.1V I/O pin voltage .............................. -0.5V to 3.8V (2) Continuous power dissipation (TA = +25°C) ..................................................................2.5W QFN-16 (3mmx3mm)..............50 ....... 12 ... °C/W θJA θJC R EC N R E OM EF W M ER D E ES N TO IG DE M NS D F A1 O R 02 (3) N O T NOTES: 1) Exceeding these ratings may damage the device. 2) The maximum allowable power dissipation is a function of the maximum junction temperature TJ (MAX), the junction-toambient thermal resistance θJA, and the ambient temperature TA. The maximum allowable continuous power dissipation at any ambient temperature is calculated by PD (MAX) = (TJ (MAX)-TA)/θJA. 3) Measured on JESD51-7, 4-layer PCB. MA120 Rev. 1.2 7/3/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 3 MA120 – ANGULAR SENSOR FOR BRUSHLESS MOTOR COMMUTATION ELECTRICAL CHARACTERISTICS Symbol Condition Min Typ Max Units R EC N R E OM EF W M ER D E ES N TO IG DE M NS D F A1 O R 02 Parameter Operating Conditions Supply voltage Supply voltage for OTP flashing Supply current for OTP (4) flashing VDD 3.0 3.3 3.6 V Vflash 3.9 4.0 4.1 V Iflash 50 100 mA Operating temperature Top -40 125 °C Applied magnetic field B 30 75 mT N O T NOTE: 4) Please see the OTP Programming section for more details about the supply circuits for OTP flashing. MA120 Rev. 1.2 7/3/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 4 MA120 – ANGULAR SENSOR FOR BRUSHLESS MOTOR COMMUTATION ELECTRICAL CHARACTERISTICS (continued) R EC N R E OM EF W M ER D E ES N TO IG DE M NS D F A1 O R 02 VDD = 3.3V, 50mT < B < 100mT, temp = -40°C to +125°C, unless otherwise noted. Parameter Symbol Sensor Output Specifications Power-up time Condition Min Typ Max Units 2 3 ms 6.0 7.7 8.8 mA ±0.9 ±1.6 ±2.0 deg ±0.5 ±1.6 ±2.5 deg -0.026 +0.026 deg/°C -0.023 +0.023 deg/mT -0.7 +0.7 deg/V 8 8 bit 558 kHz (5) Supply current At room temperature over the field range The largest value over the temperature range and field range INL at 25°C INL between -40°C to (5) +125°C Output Drift Temperature induced (5) Magnetic field induced (5) Voltage supply induced (5) Absolute Output – Serial Data output length Refresh rate Latency 488 (6) Measured at constant speed Resolution (3σ noise level) Measured by averaging over all angles 524 3 8.0 µs 8.0 bit UVW Resolution of the edge position 8 Jitter Hysteresis 0.2 bit 1.4 deg 0.27 deg Digital I/O T Threshold voltage high Threshold voltage low V 1.05 V Rising edge slew rate CL = 50pF 0.7 V/ns Falling edge slew rate CL = 50pF 0.7 V/ns O N 1.75 OTP Flash Timing Flashing time for one (6) register Period for multiple (6) registers flashing 2.6 Time between two successive flash commands 2.6 ms ms NOTES: 5) Guaranteed by design. 6) Guaranteed by characteristic test. MA120 Rev. 1.2 7/3/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 5 MA120 – ANGULAR SENSOR FOR BRUSHLESS MOTOR COMMUTATION TYPICAL CHARACTERISTICS N O T R EC N R E OM EF W M ER D E ES N TO IG DE M NS D F A1 O R 02 VDD = 3.3V, temp = 25°C, unless otherwise noted. MA120 Rev. 1.2 7/3/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 6 MA120 – ANGULAR SENSOR FOR BRUSHLESS MOTOR COMMUTATION PIN FUNCTIONS Name Description R EC N R E OM EF W M ER D E ES N TO IG DE M NS D F A1 O R 02 Package Pin # 1 2, 3, 6, 10, 11, 14 4 5 7 8 9 V MOSI CS MISO GND W 12 13 15 16 SCLK VDD U VFLASH No connection. Leave unconnected. Data in. Serial. Chip select. Serial. Data out. Serial. Ground. Incremental output. Clock. Serial. 3.3V supply. Incremental output. Voltage supply for OTP flash. Leave unconnected if not used N O T NC Incremental output. MA120 Rev. 1.2 7/3/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 7 MA120 – ANGULAR SENSOR FOR BRUSHLESS MOTOR COMMUTATION R EC N R E OM EF W M ER D E ES N TO IG DE M NS D F A1 O R 02 BLOCK DIAGRAM N O T Figure 1: Functional Block Diagram MA120 Rev. 1.2 7/3/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 8 MA120 – ANGULAR SENSOR FOR BRUSHLESS MOTOR COMMUTATION Table 1: SPI Specification OPERATION SCLK idle state SCLK readout edge CS idle state Data order High Rising High MSB first R EC N R E OM EF W M ER D E ES N TO IG DE M NS D F A1 O R 02 Timing of the Serial Interface The data link is a 4-wire serial bus complying with the serial peripheral interface (SPI) usual convention (see Table 1 and Table 2). The MagAlpha sensor operates as a slave. During one transmission, a 16-bit word can be sent to the sensor MOSI and received from the sensor MISO simultaneously (see Figure 2). Table 2: SPI Standard CPOL CPHA MODE DORD 1 1 3 0 Figure 2: SPI Timing Diagram Table 3: SPI Timing Description Min tidle Time between two subsequent transmissions 50 ns tcsL Time between CS falling edge and SCLK falling edge 50 ns tsclk SCLK period 40 ns tsclkL Low level of SCLK signal 20 ns tsclkH High level of SCLK signal 20 ns tcsH Time between SCLK rising edge and CS rising edge 25 ns tMOSI Data input valid to SCLK reading edge 15 ns tMISO SCLK setting edge to data output valid N O T Parameter MA120 Rev. 1.2 7/3/2018 Max 15 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. Unit ns 9 MA120 – ANGULAR SENSOR FOR BRUSHLESS MOTOR COMMUTATION Registers R EC N R E OM EF W M ER D E ES N TO IG DE M NS D F A1 O R 02 Table 4: Register Map No Hex Bin Bit 7 MSB 4 0x4 0100 9 0x9 1001 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 LSB - - - Z(7:0) - - - F4 - Table 5: Programming Parameters Symbol Number of Bits Zero setting Z 8 Flash register n Fn 1 Description Sets the zero position with resolution of 360/256 deg per bit ~ 1.41 deg. Flash the content of register number n See Table 6 N O T Parameters MA120 Rev. 1.2 7/3/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 10 MA120 – ANGULAR SENSOR FOR BRUSHLESS MOTOR COMMUTATION Mounting and Power Supply Decoupling For most applications, a single 100nF bypass capacitor placed close to the supply pins decouples the MA120 from power supply noise. If better decoupling is required, a larger capacitor (i.e.: 1µF to 10µF) can be added in parallel with the 100nF capacitor, and/or a serial resistor (i.e.: 10Ω) can be added on the supply line. Ensure that the capacitor is connected with low impedance paths. R EC N R E OM EF W M ER D E ES N TO IG DE M NS D F A1 O R 02 Sensor – Magnet Mounting The sensitive volume of the MA120 is confined in a region less than 100µm wide and has multiple integrated Hall devices. This volume is located both horizontally and vertically within 50µm of the center of the QFN package. The sensor detects the angle of the magnetic field projected in a plane parallel to the package’s upper surface. This means that the only relevant magnetic field is the in-plane component (X and Y components) in the middle point of the package. Rotation Direction Looking at the MagAlpha top, the angle increases when the magnetic field rotates clockwise. Figure 3 shows the zero angle of the unprogrammed MA120, where the cross indicates the sensitive point. VFLASH needs to be supplied only when flashing the memory. Otherwise, VFLASH can remain unconnected (see Figure 5). Figure 5: Connection for Supply Decoupling Figure 3: Zero Angle of Unprogrammed MA120 N O T This type of detection provides flexibility for the design of an angular encoder. The sensor only requires the magnetic vector to lie essentially within the sensor plane with an amplitude of at least 30mT. Note that the MA120 can work with fields smaller than 30mT, but the linearity and resolution performance may deviate from the specifications. The straightforward solution is to place the MA120 sensor on the rotation axis of a permanent magnet (i.e.: a diametrically magnetized cylinder) (see Figure 4). Figure 4: End-of-Shaft Mounting MA120 Rev. 1.2 7/3/2018 The package’s exposed pad can be soldered to the PCB to ensure optimal electrical, thermal, and mechanical conditions. In case the exposed pad is soldered, it is recommended to connect the pad to ground electrically. Sensor Front-End The magnetic field is detected with integrated Hall devices located in the center of the package. The angle is measured using the spinaxis method, which directly digitizes the direction of the field without any arctangent computation or feedback loop-based circuit (interpolators, etc.). The spinaxis method is based on phase detection. It requires sensitive circuitry that generates a sinusoidal signal with a phase that represents the angle of the magnetic field. The angle is then retrieved by a time-to-digital converter, which counts the time between the zero crossing of the sinusoidal signal and the edge of a constant waveform (see Figure 6). The digitized time is the front-end output. www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 11 MA120 – ANGULAR SENSOR FOR BRUSHLESS MOTOR COMMUTATION command reg. address MSB value LSB R EC N R E OM EF W M ER D E ES N TO IG DE M NS D F A1 O R 02 0 0 1 0 Once the command is sent, it is effective immediately and affects the next data sent from the MagAlpha. Top: Sine Waveform Bottom: Clock of Time-to-Digital Converter Figure 6: Phase Detection Method At the output, the front-end delivers a digital number proportional to the angle of the magnetic field at the rate of 500kHz in a straightforward and open-loop manner. Zero Setting The zero position of the MagAlpha (a0) can be programmed with 8 bits of resolution (1.40625 deg per bit). The angle streamed out (aout) can be calculated with Equation (1): aout  a fe  a0 (1) Where afe is the raw angle out of the front end. The parameter Z(7:0), which is 0 by default, determines a0 (see Table 6). This setting is valid for all output formats (i.e.: SPI and UVW). Table 6: Zero Position Z(7:0) 0 1 … 255 Zero Position a0 (deg) 0 1.41 … 358.59 N O T Programming the MA120 The MA120 incorporates three programmable registers. Each register has 8 bits of memory. When the MA120 is powered up, each of these three 8 bits of memory are set to zero, unless the register was previously stored in the onetime programmable (OTP) memory. This means that during start-up, the content of the OTP memory is copied to the registers. Once flashed, the register content can no longer be modified. To set the content of a register, a digital stream must be sent to the register consisting of the 4bit register/write command (0010), a 4-bit register address, and the 8-bit value. Reading Back the Register Content To check the content of a register to verify that the programming was successful, first send the register/read command (0001) and the 4-bit address of the register being tested. The last 8 bits of the stream are irrelevant. For instance, the value 0000 0000 can be sent: command reg. address 0 0 0 1 MSB value LSB x x x x x x x x The MagAlpha response is within the same transmission. In the first byte (simultaneous to the 4-bit read command and the 4-bit address), the MagAlpha sends the 8 bits of the measured angle A(7:0). The second byte is the content of the register being tested. After this transmission, the MagAlpha continues delivering 8-bit angles A(7:0). For example, to check the content of the register 4 (0100), which contains the zero setting, send the data: command 0 0 0 1 reg. address 0 1 0 0 MSB value LSB 0 0 0 0 0 0 0 0 Simultaneously, the MagAlpha replies: Angle out A(7:4) A(3:0) MSB value Z(7:0) LSB Output Signals The bit order of the transmitted data is MSB first and LSB last. Every 2µs, new data is transferred into the output buffer. The master device connected to the MagAlpha triggers the reading by pulling CS down. When a CS signal falling edge occurs, the data remains in the output buffer until the CS signal returns to logic 1. When CS is low, the master can read the data by sending clock pulses with a maximum frequency of 25MHz. There is no minimum frequency or timeout. See Figure 7 for a simple reading of the 8-bit data. The data stream, sent through the MOSI wire is a total of 16 bits long: MA120 Rev. 1.2 7/3/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 12 MA120 – ANGULAR SENSOR FOR BRUSHLESS MOTOR COMMUTATION R EC N R E OM EF W M ER D E ES N TO IG DE M NS D F A1 O R 02 One-Time Programmable (OTP) Programming The one-time programmable (OTP) memory can permanently store the content of the programmable registers. The OTP memory is made of poly-silicon fuses. By activating the flash command, the content of an entire register can be stored in the OTP memory. The flash command consists of setting some bits (Fn, where n is the register number) in register 9. For flashing the register, when the bit Fn is set, the register n is stored permanently. It is important to note that only one register can be flashed at a time. It is possible to operate the MagAlpha without flashing the registers (see Figure 9). Figure 7: Timing Diagram for Simple SPI Readout A full reading requires 8 clock pulses. The MA120 delivers: MSB LSB A(7:0) If the master triggers the reading faster than the refresh rate, the MagAlpha may send the same sample several times. Block Commutation - UVW The UVW output emulates the three Hall switches usually used for the block commutation of the 3-phase electric motor. The three logic signals have a duty cycle of ½ and are shifted by 60 deg relative to each other (see Figure 8). Figure 9: Circuit for Flashing N O T Figure 8: UVW Output during Rotation Burning the fuses during the flash process is irreversible. Once a register is flashed, the default values at power-up are always the same. After flashing, the content of the registers can no longer be modified. MA120 Rev. 1.2 7/3/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 13 MA120 – ANGULAR SENSOR FOR BRUSHLESS MOTOR COMMUTATION Completing Flashing 1. Connect VFLASH to VDD (4V). 2. Flash register 4: R EC N R E OM EF W M ER D E ES N TO IG DE M NS D F A1 O R 02 Flashing Procedure Prior to flashing, it is recommended to test the MagAlpha with the new settings and verify the performance of the sensor. Then, proceed with the flashing using the below steps: 1. Send the parameter to the register. 2. Read back for verification. 3. Connect VFLASH to VDD. 4. Raise VDD to 4V. 5. Set the bit corresponding to the register to be flashed in register 9. 6. Untie VFLASH. 7. Return VDD to 3.3V. 8. Switch the MagAlpha off and on. 9. Check by reading back the register content. Permanently Storing the Zero Position The following example shows how to set and flash the zero position at 50 deg. Note that permanently storing the zero position requires burning the register 4. 1. Convert into binary within a resolution of 8 bits. 50/360 * 256 = 35.56. The closest 8-bit binary value is 00100100 (50.63 deg). 2. Store the 8 MSB (00120120) of the zero position in register 4: command 0 0 1 0 reg. address 0 1 0 0 MSB value command 0 0 1 0 reg. address 1 0 0 1 MSB value LSB 0 0 0 1 0 0 0 0 3. Disconnect VFLASH from VDD. 4. Turn the MagAlpha off and on (with VDD back to the normal 3.3V value). 5. Read back registers 4 to verify that the flashing was successfully accomplished. For flashing multiple registers, send the flash command one by one. The flashing rate is specified in Sensor Output Specifications in the EC table. Note: Flashing of the OTP registers requires raising both 3.3V VDD and VFlash to 4V. Isolate other devices sharing the 3.3V VDD rail if they are not tolerant to 4V. LSB 0 0 1 0 0 1 0 0 3. Read back register 4: command 0 0 0 1 reg. address 0 1 0 0 MSB value LSB 0 0 0 0 0 0 0 0 T If the programming was correct, the MagAlpha replies with the register 4 content: N O Angle out A(15:12) A(11:8) MA120 Rev. 1.2 7/3/2018 value LSB 0 0 1 0 0 1 0 0 MSB www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 14 MA120 – ANGULAR SENSOR FOR BRUSHLESS MOTOR COMMUTATION PACKAGE INFORMATION R EC N R E OM EF W M ER D E ES N TO IG DE M NS D F A1 O R 02 QFN-16 (3mmx3mm) T NOTES: All dimensions are in mm. 2. Package dimensions do not include mold flash, protrusions, burrs, or metal smearing. 3. Coplanarity shall be 0.08. 4. Compliant with JEDEC MO-220. N O 1. 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. MA120 Rev. 1.2 7/3/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 15 MA120 – ANGULAR SENSOR FOR BRUSHLESS MOTOR COMMUTATION APPENDIX A: DEFINITIONS The smallest angle increment distinguishable from the noise. Here, the resolution is defined as 3 times σ (the standard deviation in degrees) taken over 1200 data points at a constant position. The resolution in bits is obtained with: log2(360/6σ). R EC N R E OM EF W M ER D E ES N TO IG DE M NS D F A1 O R 02 Resolution (3σ noise level) Refresh Rate Rate at which new data points are stored in the output buffer. Latency The time between the data-ready at the output and the instant at which the shaft passes that position. The lag in degrees is , where 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 noiseless sensor output and the shaft angle if the shaft zero angle coincides with the sensor zero angle. Drift Angle variation rate when one parameter is changed (e.g.: temperature, VDD) and all the others, including the shaft angle, are maintained constant. 400 sensor out (deg) 350 300 lag 250 ideal sensor output 200 150 INL 100 0 sensor out best straight fit resolution ( ? 3 ) 50 0 100 200 300 400 500 600 700 rotor position (deg) Figure A1: Absolute Angle Errors Maximum variation between two readings, successive or not, of the same shaft position at a fixed magnetic field over the complete temperature range. N O T Overall Reproducibility MA120 Rev. 1.2 7/3/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 16