Patent ID: 7061193
Filing Date: 2006-06-13
Classification: H02P

Abstract:
1. A motor drive apparatus for controlling a rotation of a motor, comprising: a position detection section for detecting a relative position between motor windings of a plurality of phases and a rotor which are included in the motor to be controlled, and outputting a position signal; a crossing detection section for making a comparison between the position signal and a reference level of the position signal, and outputting a rotation signal; an energization control signal generation section for generating, based on the rotation signal, energization control signals for sequentially energizing the motor windings of a plurality of phases; a pulse width modulation signal generation section for generating a pulse width modulation signal having a predetermined time width; a gate circuit for performing a logical operation on the energization control signals and the pulse width modulation signal; and a plurality of power transistors for supplying power to the motor windings of a plurality of phases based on the energization control signals and output signals of the gate circuit, wherein the crossing detection section includes: a comparator for making a comparison between the position signal and the reference level, and outputting a comparison result signal; a mask signal generation section for outputting a mask signal over a predetermined mask time from when the comparison result signal is reversed; and an output signal holding section for outputting the comparison result signal as the rotation signal when the mask signal is not outputted, holding a level of the comparison result signal inputted when an output of the mask signal is started, and outputting the comparison result signal based on the held level as the rotation signal when the mask signal is being outputted.