【通信应用笔记】晶体管保护TRANSIL功率和浪涌电流持续时间

【通信应用笔记】晶体管保护TRANSIL功率和浪涌电流持续时间
AN444
APPLICATION NOTE
TRANSISTOR PROTECTION BY TRANSIL:
DISSIPATION POWER AND SURGE CURRENT DURATION

INTRODUCTION
In a great number of applications, we find the diagram in Figure 1 where a Transil is used to protect a
switch which controls an inductive load.
The switch can be a bipolar or a MOS transistor.
The purpose of this paper is to calculate the dissipated power in the Transil and the pulse current duration.

Figure 1. Basic Diagram


VCC

L, r
OR




CIRCUIT MODELISATION
When the swi