1 Features

• Enhanced zero-voltage switching (ZVS) range

• Direct synchronous rectifier (SR) control

• Light-load efficiency management including:

– Burst mode operation

– Discontinuous conduction mode (DCM),

dynamic SR on/off control

• Average- or peak-current mode control with

programmable slope compensation and voltagemode

control

• Closed-loop soft-start and enable function

• Programmable switching frequency up to 1 MHz

with bidirectional synchronization

• (±3%) cycle-by-cycle current limit protection with

hiccup mode support

• 150μA start-up current

• VDD undervoltage lockout

• Wide temperature range: –40°C to +125°C

2 Applications

• Phase-shifted full-bridge converters

• Server power supply

• Industrial power systems

• High-density power architectures

3 Description

The UCC28951 controller is an enhanced version

of the UCC28950. It is a fully compatible drop-in

replacement for the UCC28950. The UCC2895x

devices use advanced control of the full-bridge in

addition to active control of the synchronous rectifier

(SR) output stage.

ZVS operation ensured over a wide range of

operating conditions, while the load current naturally

tunes the switching delays of the secondaryside

synchronous rectifiers(SR). This functionality

maximizes overall system efficiency.

Easily get started with the UCC2895x 600W phase

shifted full bridge design review/application note,

SLUA560

The 24-pin, TSSOP package complies with RoHS

requirements.