MOTOR DRIVE CIRCUIT

摘要

PROBLEM TO BE SOLVED: To prevent a motor kickback being generated in relation to switching full-waves and half-waves. SOLUTION: A speed detecting circuit detects the r.p.m. of a motor from a Hall FG signal produced from a Hall comparator based on a Hall waveform signal and delivers a speed detection signal indicative of the r.p.m. of a motor exceeding a specified value to a full-wave/half-wave switching circuit 14. At the time of full-wave/half-wave switching, the circuit 14 generates a drive-off signal which is delivered to an output stage 16 along with a full-wave/half-wave switching signal. The output stage turns the driving current off at the time of fullwave/half-wave switching.