Application Report

SLVA339A – June 2009 – Revised May 2010

High-Vin, High-Efficiency Power Solution Using DC/DC

Converter With DVFS

Ambreesh Tripathi

ABSTRACT

This reference design is intended for users designing with the TMS320C6742, TMS320C6746,

TMS320C6748, or OMAP-L138 processor. Using sequenced power supplies, this reference design

describes a system having a 12-V input voltage and a high-efficiency dc/dc converter with integrated FETs

and dynamic voltage and frequency scaling (DVFS) for a small, simple design.

Sequenced power supply architectures are becoming commonplace in high-performance microprocessor

and digital signal processor (DSP) systems. To save power and increase processing speeds, processor

cores have smaller geometry cells and require lower supply voltages than the system bus voltages. Power

management in these systems requires special attention. This application report addresses these topics

and suggests solutions for output voltage sequencing.

Contents

1

Introduction

.................................................................................................................. 2

2

Power Requirements

....................................................................................................... 2

3

Features

...................................................................................................................... 3

4

Bill of Materials

.............................................................................................................. 6

List of Figures

1

PMP4976 Reference Design Schematic

................................................................................. 4

2

Optional Circuit for DVDD_A, DVDD_B, and DVDD_C

................................................................ 5

3

Sequencing in Start-up Waveform

........................................................................................ 7

4

Efficiency vs Output Current

............................................................................................... 7

5

Efficiency vs Output Current

............................................................................................... 7

6

Efficiency vs Output Current

............................................................................................... 7

7

Efficiency vs Output Current

............................................................................................... 7

List of Tables

1

General Requirements

..................................................................................................... 2

2

PMP4976 Bill of Materials

................................................................................................. 6

1

SLVA339A – June 2009 – Revised May 2010

High-Vin, High-Efficiency Power Solution Using DC/DC Converters With DVFS

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