What the 45% duty ceiling means for your topology choice
The TL494CDRG4 is a fixed-frequency PWM controller from TI's TL494 family, designed for push-pull, half-bridge, full-bridge, and flyback topologies. Its 45% maximum duty cycle per output forces a two-transistor forward or bridge architecture in any application requiring >50% on-time — you cannot run a single-ended forward converter with this part.
Switching frequency range and transformer sizing
The oscillator runs from 1 kHz to 300 kHz. At the low end you get large magnetics but good noise margin; at 300 kHz the transformer shrinks but core losses and layout parasitics demand careful PCB design. The 7 V to 40 V supply range lets you power the controller directly from a rectified 24 V industrial bus or a 12 V battery rail without an extra regulator.