Description

AN4407

10/19

DocID025572 Rev 1

In others words, for a fixed value of Ld, (when di/dt is constant), the delay time is more and

more evident when the output power increases and the switching current level also

increases (Figure 12).

Figure 12. Relationship between stray inductance parasitic effect and current

switching duration

This theoretical situation is confirmed by experimental data during the switching instants for

both turn-off and turn-on.

1.2.1

Turn-off

If we refer to Figure 13, which shows a turn-off at high power levels, when the driver forces

stray inductance introduces a turn-off delay and consequently higher turn-off switching

losses. This can even lead to false turn-on phenomena, which can further increase the turn-

off switching power dissipation.

Figure 13. Impact of the parasitic effect during the turn-off operation

GIPG271120131039FSR

GIPG271120131042FSR