METHOD AND APPARATUS FOR CONTROLLING ROTATION SPEED OF MOTOR BY USE OF PMM

摘要

PURPOSE: A method and a device for controlling a motor by a PWM(Pulse Width Modulation) are provided to prevent instability of power in an optical disk drive of slim type. CONSTITUTION: A microcomputer checks present rpm(revolutions per minute) of a spindle motor(20). In case of the checked rpm within a damping range, the checking of the present rpm is continued(22). In case of the checked rpm out of the damping range, a step in a PWM duty control table is decided according to difference between the present rpm and a target rpm(24). Then, an increase and decrease rate is established according to the decided step for controlling the pulse duty of the PWM signal. The PWM signal is outputted.