What this PWM controller does on your board
The TL594CDR: Switching frequency spans 1 kHz to 300 kHz. Maximum duty cycle is 97 %. Supply range is 7 V to 40 V. Two totem-pole transistor-driver outputs handle external MOSFETs or bipolar switches directly.
Dead time control and frequency setting — what to watch
Dead time is adjustable via a pin, which means you can program overlap protection for half-bridge and push-pull stages without adding external logic. Frequency is set by an external RT and CT — no internal oscillator trim, so keep the RC tolerance in your BOM budget if tight regulation matters. The controller lacks clock sync, so if you are paralleling multiple converters, expect beat frequencies unless you slave them to a master timing signal externally.
It belongs in indoor power supplies, telecom rectifiers, office equipment, and appliance PSUs.