The A89303 from Allegro MicroSystems is an Automotive Qualified Three-Phase Sensorless Pump Driver IC that has been designed to drive low-power automotive BLDC motors. It requires an input voltage of 5.5 - 40 V and provides an output current of up to 3.6 A. This motor driver includes a gate driver, control logic circuit, power MOSFETs and DMOS gates, logic supply, charge pump, command line interfaces, protection circuits, and a memory unit. It implements a trapezoidal drive algorithm to minimize the time taken by the motor to attain its maximum speed. It uses either a variable Pulse Width Modulation (PWM) duty cycle input or an I2C interface with an FG data line that receives instructions from EEPROM to customize the startup and running operation of the motor.
This motor’s speed is controlled by the PWM duty cycle input which is initially measured and converted to a 9-bit number (an electrical signal), which in turn is applied to the motor windings, effectively a percentage of the power supply voltage. It consists of soft-start functions, over-current protection, over-voltage protection, and motor output short-circuit protection (OCP) circuits to prevent false triggers or overload-related damages. This AEC-Q100-qualified motor driver IC is available in a surface-mount package that measures 6.5 x 6.4 mm.
