DRIVER AND DRIVING METHOD OF STEPPING MOTOR

摘要

PROBLEM TO BE SOLVED: To provide a driver for driving a stepping motor with low loss and low vibration. SOLUTION: A reference signal generating section 110a generates a reference signal VCA representing a current limit level. In response to control from a PWM control section 120a, a bridge rectifier circuit 130a controls the supply current to a winding 19a through current chopper system to a current limit value represented by the reference signal VCA, and turns transistors 10 and 12 on during power supply interruption thus performing synchronous rectification for circulating a regeneration current to a closed circuit being formed together with the winding 19a. A synchronous rectification prohibit control section 115a prohibits the transistor 10 or 12 from being turned on during power supply interruption in a period where falloff rate of the reference signal is relatively high thus accelerating attenuation of regeneration current. COPYRIGHT: (C)2005,JPO&NCIPI