PWM controller for isolated and non-isolated topologies
The Texas Instruments TL494IDRG4 is a fixed-frequency PWM controller supporting buck, boost, flyback, forward, half-bridge, full-bridge, and push-pull topologies. The supply range of 7 V to 40 V lets it run directly off a rectified AC bus or a 12 V/24 V/36 V industrial rail without an extra regulator.
Duty cycle and topology fit
The 45% maximum duty cycle per output means each driver is off for at least 10% of the period. This dead time is inherent and suits push-pull and half-bridge converters where cross-conduction must be avoided. For a single-ended forward converter the effective duty cycle is still 45%, so the transformer reset winding must handle the volt-seconds during the off time. Dead-time control and frequency control are available as external adjustments, so the designer can set the overlap blanking and the switching frequency independently.