PREVENTION OF CONCURRENT PWM OR PSM COMMUTATIONS OF POWER SIGNALS DRIVING A VOICE COIL MOTOR (VCM) TO REDUCE S/N RATIO DEGRADATION OF LOW LEVEL SIGNAL LINES OF A R/W HEAD

摘要

A method of preventing concurrent or quasi-concurrent commutations of a pair of phase shift modulation (PSM) drive signals of an output bridge stage driving an electrical load includes establishing a threshold level of a programmed current level to be transmitted though the electrical load. The method also includes, if the programmed current level is lower than the threshold level, enhancing a time offset between commutation edges of the pair of PSM drive signals by a minimum time.