Introduction, Features | Texas Instruments HPA070 guide

SLUU186 − March 2004

TPS40055-Based Design Converts 12-V Bus to 1.8 V at 15 A (HPA070)

Mark Dennis		System Power
	Contents
1	Introduction	. . . . . . . . . . . . 4
2	Features	. . . . . . . . . . . . 4
3	Schematic	. . . . . . . . . . . . 5
4	Component Selection	. . . . . . . . . . . . 6
5	Test Setup	. . . . . . . . . . . 10
6	Test Results and Performance Data	. . . . . . . . . . . 11
7	EVM Assembly Drawing and PCB Layout	. . . . . . . . . . . 12
8	List of Materials	. . . . . . . . . . . 15
9	References	. . . . . . . . . . . 16
1	Introduction
	In many modern electronic applications there is a growing demand for circuits to convert a12-V bus to digital
	voltages as low as, but not limited to 1.8 V. The current requirements can range from below 1 A to over 15 A.
	For high-efficiency and small circuit size the TPS40055 wide-input synchronous buck controller can be used
	to provide the necessary control and drive functions to implement these converters. The TPS40055EVM−001
	operates at 300 kHz and delivers 1.8 V at 15 A with efficiency over 90% for much of the load range, and a full
	load efficiency of 88%.

The TPS40055 synchronous buck controller offers a variety of user programmable functions such as operating frequency, soft-start time, voltage feed-forward, high-side current limit, and external loop compensation. This controller also provides a regulated 10-V bias voltage which supplies onboard drivers for the N-channel switch and synchronous rectifier MOSFETs, utilizing adaptive gate drive logic to prevent cross conduction of the power MOSFETs.[1]

2 Features

The specification of this design is as follows:

D92% peak efficiency at 6 A

D88% peak efficiency at 15 A

D1.8V output at 15 A

DVIN range from 10 VDC to 14 VDC

DSmall circuit size 1.4” x 2.5” SMT design, components on single side

DLine/load regulation < 0.5%

DHigh-frequency 300-kHz operation

DTransient deviation 60 mV with 10-A load step

4TPS40055-Based Design Converts 12-V Bus to 1.8 V at 15 A (HPA070)

Mark Dennis

System Power

Contents

Introduction

2 Features