Application Report

SLVA342A – June 2009 – Revised May 2010

Simple Power Solution Using LDOs

Ambreesh Tripathi

ABSTRACT

This

reference

design

helps

those

desiring

to

design-in

the

TMS320C6742,

TMS320C6746,

TMS320C6748, and OMAP-L138. This design, employing sequenced power supplies, describes a system

with an input voltage of 3.3 V, and uses LDOs for a small, simple system.

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

List of Material

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

List of Figures

1

PMP4980 Reference Design Schematic

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

2

Optional Circuit for DVDD_A, DVDD_B, and DVDD_C

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

3

Sequencing in Start-Up Waveform

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

List of Tables

1

Power Requirements

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

2

PMP4980 List of Material

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

1

SLVA342A – June 2009 – Revised May 2010

Simple Power Solution Using LDOs

Copyright © 2009–2010, Texas Instruments Incorporated