VIN

SW

AGND

FB

PGOOD

EN

SS/TRK

VCC

COMP

LM20242

RT

BOOT

GND

L

LM20242

www.ti.com

SNVS534D – OCTOBER 2007 – REVISED MAY 2008

Check for Samples: LM20242

1

FEATURES

DESCRIPTION

The LM20242 is a full featured 1MHz capable

23

•

2A Output Current, 3.7A Peak Current

synchronous buck regulator capable of delivering up

•

130 m

Ω/110 mΩ Integrated Power MOSFETs

to 2A of load current. The current mode control loop

•

1.5% Output Voltage Accuracy

is externally compensated with only two external

components, offering both high performance and

•

Current Mode Control, Selectable

ease of use. The device is optimized to work over the

Compensation

input voltage range of 4.5V to 36V making it well

•

Resistor Programmed, 1MHz Capable

suited for high voltage systems.

Oscillator

The device features internal Over Voltage Protection

•

Synchronous Rectifier with Diode Emulation

(OVP) and Over Current Protection (OCP) circuits for

•

Adjustable Output Voltage Down to 0.8V

increased system reliability. A precision Enable pin

and integrated UVLO allows the turn on of the device

•

Compatible with Pre-Biased Loads

to be tightly controlled and sequenced. Startup inrush

•

Programmable Soft-Start With External

currents are limited by both an internally fixed and

Capacitor

externally adjustable soft-start circuit. Fault detection

•

Precision Enable Pin with Hysteresis

and

supply

sequencing

are

possible

with

the

integrated PGOOD circuit.

•

OVP, UVLO Inputs and PGOOD Output

•

Internally Protected with Peak Current Limit,

The LM20242 is designed to work well in multi-rail

Thermal Shutdown and Restart

power supply architectures. The output voltage of the

device can be configured to track a higher voltage rail

•

Accurate Current Limit with Frequency

using the SS/TRK pin. If the output of the LM20242 is

Foldback

pre-biased at startup it will not sink current to pull the

•

Non-Linear Current Mode Slope Compensation

output low until the internal soft-start ramp exceeds

•

HTSSOP Exposed Pad Package

the voltage at the feedback pin.

The LM20242 is offered in an exposed pad 20 pin

APPLICATIONS

HTSSOP package that can be soldered to the PCB,

eliminating the need for bulky heatsinks.

•

Simple to Design, High Efficiency Point of

Load Regulation from a 4.5V to 36V Bus

•

High Performance DSPs, FPGAs, ASICs and

Microprocessors

•

Communications Infrastructure, Automotive

Simplified Application Circuit

1

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2

PowerWise is a registered trademark of Deere and Company.

3

All other trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Copyright © 2007–2008, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.