Patent ID: 7164245
Filing Date: 2007-01-16
Classification: H02P

Abstract:
1. A brushless motor drive device for driving a multi-phase motor, comprising: a current detecting circuit for generating a current detection signal representative of a motor drive current flowing through the multi-phase motor; an error determining circuit for generating a current error signal representative of a difference between a current command signal and the current detection signal; a sensing circuit for generating a plurality of sensing signals in response to variations in a magnetic field of the multi-phase motor; a signal synthesizing circuit for converting the plurality of sensing signals into a plurality of drive signals, such that an amplitude of each of the drive signals is determined in accordance with the current error signal; a comparing circuit for comparing the plurality of drive signals with a reference signal so as to generate a plurality of pulse signals; and a switching circuit coupled between a drive voltage source and the multi-phase motor and controlled by the plurality of pulse signals for driving the multi-phase motor, characterized in that: the signal synthesizing circuit includes a calibrating circuit for adjusting the current error signal in accordance with an amplitude of any of the sensing signals.