AN574 Datasheet, PDF (1/4 Pages) Maxim Integrated Products – App Note 101: Using the Secure Microcontroller Watchdog Timer

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APPLICATION NOTE
TRANSIL™/TRISIL™ COMPARISON
A. Bremond
1. INTRODUCTION
To protect a sensitive device there are two
different approaches.
The first one is to use series protectors, the
second one parallel suppressors. The
technologies used in both cases are such
that the series devices are suitable for long
duration surges, while parallel protectors are
very efficient for the high current short
duration stresses which represent the great
majority of cases.
For the parallel protection solutions, two
philosophies can be used. The first one is
represented by a breakdown based device
and the second one by a breakover based
protector, respectively known as the Transil
and the Trisil.
Figure1A : Classical schematic of parallel protection
OVER-
-VOLTAGE
SOURCE
R_S
P
DEVICE
TO BE
PROTECTED
2. TRANSIL / TRISIL COMPARISON
2.1. Electrical characteristics
Figure 1B : Electrical characteristics
TRANSIL
I
TRISIL
I
-V_BR
V
V_BR
-V_BO
V
V_BO
The Transil is a clamping device which
suppresses all overvoltages above the
breakdown voltage (VBR)
The Trisil is a crowbar device which switches on
when overvoltages rise up to the breakover
voltage (± VBO).
AN574/1197
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