APPARATUS AND METHOD FOR DRIVING MOTOR

PROBLEM TO BE SOLVED: To provide an apparatus and method for driving a motor capable of reducing the vibration and noise of the motor. SOLUTION: This motor driving device drives a sensorless multiphase brushless motor which includes a rotor position detecting portion and a clock generating portion. The rotor position detecting portion generates an excitation phase switching signal which is a sequential pulse signal mated with the position of the rotor. Additionally, the excitation phase switching signal is divided to sub-zones, and a rotor position signal which takes a first state in one sub-zone is generated. The clock-generating portion includes a clock generator for generating a first clock signal, a clock generator for generating a second clock signal at a higher frequency, and a clock switching portion for switching the clock signal so as to output the first clock signal as a reference clock for PWM control, when the rotor position signal is in a first state and output the second clock signal as the reference clock for PWM control, when the rotor position signal is in a second state. COPYRIGHT: (C)2008,JPO&INPIT