PWM controller with wide topology support — now obsolete
The TL494CDBRG4 is a fixed-frequency PWM controller from Texas Instruments that supports step-up, step-down, and step-up/step-down regulation across buck, boost, flyback, forward converter, full-bridge, half-bridge, and push-pull topologies. Switching frequency spans 1 kHz to 300 kHz, and the supply range covers 7 V to 40 V, suiting it for industrial auxiliary supplies, telecom bricks, and off-line flyback converters.
Switching frequency and duty-cycle limits
The oscillator is programmable from 1 kHz to 300 kHz via an external RT and CT. Maximum duty cycle is 45 % per output, which limits the usable range in single-ended topologies like flyback and forward converters. Two transistor-driver outputs deliver positive drive with dead-time control and frequency control available on the control pins.
Housed in a 16-SSOP (0.209", 5.30 mm width) surface-mount package, supplier device package 16-SSOP. The part does not include a synchronous rectifier output or clock-sync capability; it is a classic voltage-mode PWM controller.
Sourcing an obsolete PWM controller
With an official lifecycle status of Obsolete, the TL494CDBRG4 is no longer manufactured by Texas Instruments.