The SA828 PWM generator has been designed to provide waveforms for the control of variable speed AC machines, uninterruptible power supplies and other forms of power electronic devices which require pulse width modulation as a means of efficient power control. The six TTL level PWM outputs (Fig. 2) control the six switches in a three-phase inverter bridge. This is usually via an external isolation and amplification stage. The SA828 is fabricated in CMOS for low power consumption.