Choosing the appropriate Schottky diode

AN3361

6/15

Doc ID 018589 Rev 1

2

Choosing the appropriate Schottky diode

Schottky diode choice for reverse battery protection is determined by the electronic module

normal operating current on the one hand, and the need to pass the ISO 7637-2 pulse tests

on the other. Each module has its own normal operating current, which is defined by its

characteristics. So here we will consider only the method to choose an appropriate Schottky

diode to meet the ISO 7637-2 requirements.

2.1

Load-dump surge compatibility criteria

datasheet.

2.1.1

Load-dump peak current calculation

Figure 6 shows the current shape through the Schottky diode during a load-dump surge

according to the schematic described in Figure 5.

Figure 5.

Pulse 5b surge test schematic

Electronic module

I

p

V

cl

V

F

Schottky diode

R = 0.5

i

Ω

Pulse 5b:

V

=13.5 V

V = [24-48 V]

t = 300 ms

bat

g

ps