Patent ID: 8742713

Claim:
A circuit for driving a multi-phase brushless DC motor, the motor having a motor shaft and a plurality of motor windings, the circuit comprising: a position signal generator configured to generate a plurality of position signals, each one of the plurality position signals representative of a rotational position of the motor shaft; a pattern generator coupled to receive selected ones of the plurality of position signals, and configured to generate a plurality of pattern signals each pattern signal a predetermined number of degrees apart from other ones of the plurality of pattern signals, each one of the patter signals having respective first and second states; a modulation circuit coupled to receive the plurality of pattern signals and configured to generate a corresponding plurality of pulse width modulated (PWM) signals, each one of the plurality of pulse width modulated signals having a respective active region comprising a pulse width modulated waveform only during a selected one of the first or second states of a respective one of the plurality of pattern signals, wherein the active regions of each one of the plurality of pulse width modulated (PWM) signals start at the same phase and at the same signal value; and a plurality of drive circuits coupled to receive a plurality of signals representative of the plurality of pulse width modulated signals, wherein the plurality of drive circuits is configured to generate a plurality of drive signals related to the plurality of pulse width modulated signals, each one of the plurality of drive signals configured to couple to one end of a respective one of the plurality of motor windings.