AN1826 - APPLICATION NOTE

3/5

Fig. 4: Varistor and Transil™ diode EOS electrical behaviors.

performed with 10A peak current, in such a condition the Varistor clamps at 37.2V while remaining voltage

across the Transil™ in the same condition is only 24.6V. That means in such a surge condition the

protected IC's input will see 12.6V less in case of Transil™ diode use; that leads to a better clamping factor

for Transil™ diode versus varistor.

Fig. 5: Varistor and Transil™ diode ESD electrical behaviors.

Current

10.0V

Ch2

Ch2

200mV

M 5.00µs

96mV

Voltage

Tek Run: 10.0MS/s

Sample

T

Trig?

Ch1

2

[

]

1

Varistor

V

@10A=37.2V

CL

Current

5.0 V

Ch2

200mV

M 5.00µs

96mV

Voltage

Tek Run: 10.0MS/s

Sample

T

Trig?

Ch1

[

]

2

1

Ch2

Transil™ diode

V

@10A=24.6V

CL

Varistor

Transil™

37.2

24.6

18.4

15.2

2.02

1.62

Table 1: Clamping factor comparison.

Varistor

Transil™ diode