ZHCSH31B August 2017 – February 2018 DRV10987
The DRV10987 device is a three-phase sensorless motor driver with integrated power MOSFETs that provides drive-current capability up to 2 A continuously. The device is specifically designed for low-noise, low-external-component-count motor-drive applications. The device is configurable through a simple I2C interface to accommodate different motor parameters and spin-up profiles for different customer applications.
A 180° sensorless control scheme provides continuous sinusoidal output voltages to the motor phases to enable ultra-quiet motor operation by keeping the electrically induced torque ripple small.
The DRV10987 device features extensive protection and fault-detection mechanisms to ensure reliable operation. Voltage surge protection prevents the input VCC capacitor from overcharging, which typically occurs during motor deceleration. The device provides overcurrent protection without the need for an external current-sense resistor. Rotor-lock detection is available through several methods. These methods can be configured with register settings to ensure reliable operation. The device provides additional protection for undervoltage lockout (UVLO) and for thermal shutdown.
The commutation control algorithm continuously measures the motor phase current and periodically measures the VCC supply voltage. The device uses this information for BEMF estimation, and the information is also provided through the I2C register interface for debug and diagnostic use in the system, if desired.
A step-down regulator in buck mode efficiently steps down the supply voltage. The output of this regulator provides power for the internal circuits and can also be used to provide power for an external circuit such as a microcontroller. If providing power for an external circuit is not necessary (and to reduce system cost), configure the step-down regulator as a linear regulator by replacing the inductor with a resistor.
The DRV10987 device has a flexible interface, capable of supporting both analog and digital inputs. In addition to the I2C interface, the device has FG, DIR, and SPEED pins. SPEED is the speed–command input pin. DIR is the direction–control input pin. FG is the speed indicator output, which shows the frequency of the motor commutation.
EEPROM is integrated in the DRV10987 device as memory for the motor parameter and operation settings. EEPROM data transfers to the registers after power-on.
The DRV10987 device can also operate in register mode. If the system includes a microcontroller communicating through the I2C interface, the device can dynamically update the motor parameters and operation settings by writing to the registers. In this configuration, the EEPROM data is bypassed by the register settings.