OPTICAL DISC REPRODUCTION DRIVE HAVING A DC/DC CONVERTER

摘要

PURPOSE: A CD-ROM(Compact Disk-Read Only Memory) drive is provided to accelerate a spindle motor regardless rotational conditions of the spindle motor. CONSTITUTION: A spindle motor(16) is rotated in a CAV(Constant Angular Velocity) servo drive method by a spindle motor drive signal generated from a spindle motor driver(30). A DSP(Digital Signal Processor,20) outputs PWM(Pulse Width Modulation) signals to the spindle motor driver according to an rpm(revolutions per minute) control signal of a microcomputer(26). The microcomputer detects the current rpm of the spindle motor by counting FG(Frequency Generation) pulse of the spindle motor driver and outputs an rpm control signal. The spindle motor driver outputs a spindle motor drive signal for accelerating/decelerating the spindle motor according to duty of the PWM signal. The spindle motor driver outputs the FG signals into frequency/voltage-converted FG pulse. A DC-DC converter(32) boosts voltage level of 5V into 6V and supplies to the spindle motor. Thereby, a CD-ROM drive accelerates the spindle motor.