herunterladen
1 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
Figure 1
.
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:
l
The MOSFET gate driver.
l
The microcontroller’s 3.3 V or 5 V supply.
l
The power supply voltage at 13 V.
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
Verzeichnis
