In order to further explain the P-i-N diode reverse
recovery process, in Fig.2 DM is the tested device, Vdc is the
bus voltage, vd is the diode voltage, id is the diode current, IL
is the load current, and vce is the collector-emitter voltage of
SM. SM is turned on and off to form the dynamic switching
test for DM. The experimental waveforms of a high power Pi-N
diode at a certain ambient temperature are shown in
Fig.3, along with the corresponding veE waveforms induced
by the reverse recovery current. The complete P-i-N diode
turn-off transition can be divided into four stages as follows:
before time t0, the forward current IL flows though diode DM,
inductor Lload and parasitic inductance Ls1. The power diode
is in the forward biased state with a low on-state voltage
drop. Switch SM is in the turn-off state, while the voltage
across SM is equal to bus voltage Vdc. Switch turn-on is
initiated by applying gate voltage.