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Introduction

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Features

User's Guide

SLUU109B – December 2001 – Revised February 2009

Using the UCC3895 in a Direct Control Driven

Synchronous Rectifier Applications

The UCC3895EVM-001 evaluation module (EVM) is an isolated 48-V input phase-shifted full-bridge

converter providing an output of 3.3 V at 15 A. The AB outputs of the UCC3895, in this application are

used for direct control driven synchronous rectification. No demodulation of the AB phase shift clock

signals is necessary to produce fully operational synchronous rectification gate drive signals yielding a

significant overall efficiency increase.

Operating in peak current-mode control, this EVM highlights the many benefits of using the UCC3895

advanced phase-shift PWM controller for direct control of synchronous rectification. This user's guide

provides the schematic, component list, assembly drawing, artwork and test setup necessary to evaluate

the UCC3895 in a typical control-driven synchronous rectification application.

• 48-V typical input (36 V < VIN < 72 V), 2:1 input range

• 3.3-V output at 15 A

DC

• Control driven synchronous rectifier current doubler output

• 1500-V input to output isolation

• Compact size, low profile (3.5" x 2.5" x 0.5")

• Peak current-mode control

• 400-kHz oscillator frequency (200-kHz operating frequency)

• Fixed-frequency operation

• 87% efficiency

• Single side OTS surface-mount components

• Short circuit protection

Using the UCC3895 in a Direct Control Driven Synchronous Rectifier Applications

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SLUU109B – December 2001 – Revised February 2009

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