<Dual-In-Line Package Intelligent Power Module>
1200V Mini DIPIPM with BSD Series APPLICATION NOTE
Publication Date: September 2015
40
FWDi recovery characteristics can be approximated by the ideal curve shown in Fig.3-2-1, and its
dynamic loss can be calculated by the following expression:
Fig.3-2-1 Ideal FWDi recovery characteristics curve
4
trr
Vcc
Irr
Psw
Recovery occurs only in the half cycle of the output current, thus the dynamic loss is calculated by:
dx
fc
x
Icp
trr
Vcc
x
Icp
Irr
dx
fc
x
Icp
trr
Vcc
x
Icp
Irr
)
sin
(@
)
sin
(@
8
1
4
)
sin
(@
)
sin
(@
2
1
2
2
Attention of applying the power loss simulation for inverter designs
・
Divide the output current period into fine-steps and calculate the losses at each step based on the
actual values of PWM duty, output current, V
CE(sat)
, V
EC
, and Psw corresponding to the output
current. The worst condition is most important.
・
PWM duty depends on the signal generating way.
・
The relationship between output current waveform or output current and PWM duty changes with
the way of signal generating, load, and other various factors. Thus, calculation should be carried
out on the basis of actual waveform data.
・
V
CE(sat)
,V
EC
and Psw(on, off) should be the values at Tj=125°C.
trr
Vcc
Irr
I
EC
V
EC
t
