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1 - Introduction

The TSM108 is a step down controller that features constant voltage and constant current regulation. It

can drive either a P-channel Mosfet or a PNP bipolar transistor. The principle of operation of the TSM108

is widely described in the application note attached to the datasheet. The goal of this document is to

describe the TSM108 Evaluation Board.

The Evaluation Board was designed to allow different converter configurations. Several options for power

semiconductor footprints are available on the PCB in order to make it adaptable to a wide range of

converter output power. In a first step, this application note will describe the typical application. Then the

various options available on the Evaluation Board PCB will be explained.

2 - TSM108 typical application

2.1 Description

The TSM108 is especially suited for cigarette lighter accessories. The typical application described in this

note is a battery charger with the following characteristics:

Input voltage: Vin = 12V

Output voltage: Vout = 6V

Maximum output current: Iout = 800mA

A picture of the Evaluation Board in the typical application configuration is shown on Figure 1. The related

schematic is described on Figure 2.

Figure 1 : TSM108 Evaluation Board

AN1695

APPLICATION NOTE

TSM108 EVALUATION BOARD

12V to 6V DC/DC CONVERTER

January 2003

by Anthony BOIMOND