Texas Instruments TPS40051 manual Introduction, Features

Page 4

SLUU161 – April, 2003

TPS40051-Based Design Converts 12-V Bus to 1.8 V at 15 A (SLUP195)

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 TPS40051 wide-input synchronous buck controller can be used

 

to provide the necessary control and drive functions to implement these converters. The TPS40051EVM–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 TPS40051 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

4TPS40051-Based Design Converts 12-V Bus to 1.8 V at 15 A (SLUP195)

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Contents User’s Guide EVM Important Notice Dynamic Warnings and Restrictions Features IntroductionSchematic TPS40051EVM-001 SLUP195 SchematicComponent Selection TPS40051 Device SelectionFrequency of Operation + R2 + f 17.82 10 *6 * 23 kInductance Value Uvlo CircuitryInput capacitor selection Output Capacitor Selection Mosfet selectionSnubber Component Selection Short Circuit ProtectionCompensation Components Test Setup DC Input SourceOutput Load Oscilloscope Probe Test JacksTest Results / Performance Data Efficiency and Power LossClosed Loop Performance EVM Assembly Drawing and PCB Layout Output Ripple and Transient ResponseTop Side Copper Internal Layer 2 Copper List of Materials TPS40051EVM-001 SLUP195 List of MaterialsReferences Important Notice

TPS40051 specifications

Texas Instruments TPS40051 is a highly integrated, synchronous step-down (buck) switching regulator designed to deliver power efficiently and effectively to various applications. This device is particularly well-suited for powering FPGAs, DSPs, microcontrollers, and other digital devices that require a stable voltage supply with high efficiency.

One of the main features of the TPS40051 is its ability to operate from a wide input voltage range of 4.5V to 17V. This flexibility makes it suitable for a variety of power sources, including battery-operated systems and traditional AC/DC power supplies. The output voltage can be adjusted from 0.8V to 85% of the input voltage, making it adaptable to different load requirements and application scenarios.

The TPS40051 employs a constant frequency, voltage mode control scheme, which results in improved transient response and stability. The device operates with a fixed switching frequency that can be set between 100kHz and 1MHz, allowing designers to optimize their designs for efficiency or minimize electromagnetic interference (EMI). The low RDS(on) of the integrated MOSFETs reduces conduction losses, contributing to the overall high efficiency of the solution, often exceeding 90%.

In terms of protection features, the TPS40051 includes overcurrent protection, thermal shutdown, and under-voltage lockout, which enhance the reliability of the system. These features allow the device to maintain safe operating conditions in various scenarios, protecting both the regulator and the load.

Another significant characteristic of the TPS40051 is its ability to operate in a Power Good mode. This feature provides feedback to the system regarding the status of the output voltage, allowing for better system monitoring and control. Additionally, it has an adjustable soft-start feature, which helps prevent inrush current during power-up, further protecting sensitive loads.

The TPS40051’s compact package options and its integration of features make it a flexible choice for designers looking to implement efficient power management solutions. Whether used in industrial, automotive, or consumer electronics applications, the TPS40051’s robust performance and adaptability make it an excellent choice for modern power supply designs.
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