DocID025572 Rev 1

7/19

AN4407

Description

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Figure 7. Section of the driving network related to the demo board

It is important to ensure that the current flowing through Rx is negligible compared to the

current flowing through the sensing resistor Rs.

1.2

Parasitic inductance effects

Usually, to drive the fast switching super-junction MOSFET, it is necessary to reduce the

impact of the package and the parasitic effects introduced by the layout. This aspect is well

known for low voltage MOSFETs where high current values are commonly detected. But

what happens when a high voltage device is used on an application where clearance and

creepage distance requirements must be considered?

This section demonstrates the impact of the parasitic inductance of the single source lead

deriving from the connection of the lead with the die (Figure 8 and Figure 9).

The impact of the package is limited by the internal wire bonding. There are several ways to

calculate the magnitude of this effect, the first being to analyze the parasitic inductance due

to a wire.

GIPG211120131744FSR