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.