Implementation of Brushless DC Motor Control Chip Based on PWM Technique

In this paper, a brushless DC motor control chip based on PWM technique is proposed. It integrates the rotor position decoder and includes functions for forward and reverse rotation as well as angle selection. The chip integrates the functions of under-voltage protection, over-current protection, and over-temperature protection. This integration enhances the functionality of the chip. The width of the PWM signals is controlled by an external modulation input voltage. Motor speed is controlled by generating a PWM signal with a variable pulse width. The chip outputs six control signals that can be used to control a three-phase brushless motor. The chip design is completed using a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.25\mu \mathrm{m}$</tex> BCD process, and the simulation and test results are consistent. The chip is easy to control, occupies a small area, and can reliably drive and control the motor.