DRV10975 Datasheet, PDF (9/57 Pages) Texas Instruments – 12-V, Three-Phase, Sensorless BLDC Motor Driver

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9 Detailed Description
DRV10975
SLVSCP2 – JANUARY 2015
9.1 Overview
The DRV10975 is a three-phase sensorless motor driver with integrated power MOSFETs, which provide drive
current capability up to 1.5 A continuous. The device is specifically designed for low-noise, low external
component count, 12-V 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 DRV10975 features extensive protection and fault detect mechanisms to ensure reliable operation. Voltage
surge protection prevents the input Vcc capacitor from overcharging, which is typical during motor deceleration.
The devices provides overcurrent protection without the need for an external current sense resistor. Rotor lock
detect 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 buck switching regulator 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 buck switching
regulator as a linear regulator by replacing the inductor with resistor.
TI designed the interfacing to the DRV10975 to be flexible. In addition to the I²C interface, the system can use
the discrete FG pin, DIR pin, and SPEED pin. SPEED is the speed command input pin. It controls the output
voltage amplitude. 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 DRV10975 as memory for the motor parameter and operation settings. EEPROM
data transfers to the register after power-on and exit from sleep mode.
The DRV10975 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 parameter and operation settings by
writing to the registers. In this configuration, the EEPROM data is bypassed by the register settings.
Copyright © 2015, Texas Instruments Incorporated
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