Fuji Electric Co., Ltd.
3-12
MT6M12343 Rev.1.0
Dec.-2016
Chapter 3
Detail of Signal Input/Output Terminals
3) Setting the bootstrap capacitance for Initial charging
The initial charge of the bootstrap capacitor is required to
start-up the inverter.
The pulse width or pulse number should be large enough
to make a full charge of the bootstrap capacitor.
For reference, the charging time of 10
F capacitor
through the internal bootstrap diode is about 2ms.
Main Bus voltage
V
(P-N)
ON
HVICs and LVIC
supply voltage
Vcc
Upper side IGBT
supply voltage
Vb(*)
Gate signal of
Lower side IGBT
Initial charging time
Start
PWM
Fig.3-11 Circuit diagram of initial charging
operation
Fig.3-12 Timing chart of initial charging operation
Vcc
<HVIC>
GND
Vs
OUT
VB
IGBT(H)
IGBT(L)
Vcc
C
D
R
OFF
ON
<BSD>
COM
N(U,V,W)
U,V,W
P
VB(U,V,W)
V
CCH
