Controller for brushless DC motor with low torque ripple and method therefor

摘要

A controller for a BLDC motor includes a pulse width modulator and a control circuit. The pulse width modulator provides at least one phase control signal for a corresponding phase of the BLDC motor with a pulse width determined by a duty cycle signal. The duty cycle adjustment circuit has an input for receiving the at least one phase control signal, and an output for providing a corresponding modified phase control signal by adjusting widths of pulses of the at least one phase control signal when an average current in said corresponding phase exceeds a threshold.

主权项

1. A controller for a BLDC motor, comprising:
a pulse width modulator for providing at least one phase control signal for a corresponding phase of the BLDC motor with a pulse width determined by a duty cycle signal; and a duty cycle adjustment circuit having a first input for receiving said at least one phase control signal, a second input for receiving a measured current signal, and an output, wherein said duty cycle adjustment circuit integrates said measured current signal to form an average current signal, and provides a corresponding modified phase control signal by adjusting widths of pulses of said at least one phase control signal when said average current signal in said corresponding phase exceeds a threshold.