Datasheet

User's Guide

SLUU441A–September 2010–Revised October 2011

Half-Bridge DC-to-DC Converter

With Secondary-Side Control

1 Introduction

This EVM is to aid in evaluating UCC28250 PWM device with secondary-side control in DC-to-DC

symmetrical half-bridge converter topology. The targeted application is telecom module design with

nominal 48-V input. UCC28250 is a PWM controller that can be used for primary-side control or

secondary-side control. In this EVM, UCC28250 is placed at the secondary side to make secondary-side

control.

2 Description

The EVM is a 100-W symmetrical half-bridge DC-to-DC converter that converts 36 V to 75 V DC to a

regulated output voltage 3.3 V and maximum 30-A load current.

2.1 Typical Applications

• Telecom Power Supplies with Secondary-Side Control

• Server Systems

• Datacom

• DSP’s, ASIC’s, and FPGA’s

2.2 Features

• Start up from telecom input voltage 36 V to 75 V DC with initial assistance of external auxiliary supply

on the secondary side.

• Regulated output voltage 3.3 V with maximum 30-A load current.

• Smooth and monotonic output voltage turn on with up to 90% pre-biased output voltage.

• Output voltage regulation from no load to full load, and from low line to high line.

• Secondary-side Enable ON/OFF function and manual switch.

• Secondary-side control.

• Voltage-mode control.

• Control-driven synchronous rectifier.

• Non-latching output over voltage protection.

• Hiccup over current protection.

• Telecom basic isolation from primary to secondary 1500 V.

CAUTION

Before doing any test with this EVM, please read this document especially

Section 3 through Section 6. Without a thorough reading of this document,

strange behavior of operation and possible damage may be resulted in the test.

Half-Bridge DC-to-DC Converter —With Secondary-Side Control SLUU441A–September 2010– Revised October 2011

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