User's Guide

SNVA377D – March 2009 – Revised April 2013

AN-1908 LM2842 Evaluation Board

1

Introduction

The LM2842 is a PWM DC/DC buck (step-down) regulator. With a wide input range from 4.5V to 42V, it is

suitable for a wide range of applications from automotive to power conditioning from unregulated sources.

The LM2842 evaluation board is designed to provide the design engineer with a fully functional power

converter based on the buck topology to evaluate the LM2842 series of buck regulators. The evaluation

board comes populated with the LM2842XMK-ADJL but can easily be modified to accommodate any of

the LM2842 regulator ICs.

2

Features

•

4.5V to 42V Input Voltage Range

•

3.3V Output Voltage

•

Up to 600 mA Output Current

•

89% Efficiency at 300 mA

•

Switching Frequency of 550 kHz

•

Frequency Foldback Current Limit of 1A

•

Internal Compensation

3

Shutdown Operation

The evaluation board includes a 3 pin header and a jumper to select whether the device is on or off.

Placing the jumper in the "ON" position ties SHDN to VIN and enables the device. Placing the jumper in

the "OFF" position ties SHDN to GND and disables the device. The jumper may be removed and a logic

signal may be applied to the center pin to test startup and shutdown of the device.

4

Adjusting the Output Voltage

The output voltage can be changed from 3.3V to another voltage by adjusting the feedback resistors using

the following equation:

V

(1)

Where V

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1

SNVA377D – March 2009 – Revised April 2013

AN-1908 LM2842 Evaluation Board

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