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INTRODUCTION

This application note gives a simple functional

description of the TD220/221, which is a standard

circuit designed with an industrial application in

mind, see

However, the TD220/221, together with other ST

components, such as an ST7 microcontroller, and

a MOSFET device, can provide a flexible, high-

performance, power management solution that

may be broadly applied to applications in the

industrial fields.

A common problem in such off-line applications is

the generation of a low voltage power supply for

the various control ICs.

Because of this, the TD220/221 includes a

"Two-Point Regulator” that enables control of a

switching charge pump connected.

The charge pump diodes are integrated within the

TD220/221, and a switch disables the charge

pump when the nominal voltage is reached.

The main advantage of the TD220/221 is that it

integrates, in a single SO8 package, 3 block

functions—voltage regulation, power supply and

power MOS driver—at a very reasonable price.

In typical applications, the TD220/221 manages

the following functions:

Fig. 1: Typical application schematic of the TD220/22

APPLICATION NOTE

AN1707

TD220/221

Gate Driver with Vreg and Two-Point Regulator

by Giuseppe Scuderi

Revision B

1/5

October 2003