AN4671

How to minimize switching losses

DocID027654 Rev 1

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These figures demonstrate that the largest turn-off losses occur during voltage rise time,

which can be significantly shortened by lowering the gate resistance. Moreover, the small

gate charge needed to switch the device and the low transconductance value:

•

Ω (see Figure 4)

•

Ω

(see Figure 5)

The use of a negative voltage to turn off the MOSFET helps reduce turn-off losses further

since it increases the voltage drop across the gate resistance, thus enabling faster charge

when the off voltage moves from 0 V down to -5 V.