UCC1583,UCC2583,UCC3583,pdf(Sw

The UCC3583 is a synchronizable secondary side post regulator for precision regulation of the auxiliary outputs of multiple output power supplies. It contains a leading edge pulse width modulator, which generates the gate drive signal for a FET power switch connected in series with the rectifying diode. The turn-on of the power switch is delayed from the leading edge of the secondary power pulse to regulate the output voltage. The UCC3583 contains a ramp generator slaved to the secondary power pulse, a voltage error amplifier, a current error amplifier, a PWM comparator and associated logic, a gate driver, a precision reference, and protection circuitry.

The ramp discharge and termination of the gate drive signal are triggered by the synchronization pulse, typically derived from the falling edge of the transformer secondary voltage.