MT6M15962a
© Fuji Electric Co., Ltd. All rights reserved.
5.7 Control power supply under voltage protection (UV) operation during IGBT chips over heating
protection (
T
jOH
) operation (1)~(3)
• When the IGBT chip surface temperature
T
vj
exceeds
T
jOH
for 1ms continuously, an alarm signal is
output and the IGBT is turned off softly
※
1
. (1)
• If
V
CC
drops below
V
UV
before the elapse of
t
ALM(TjOH)
, the alarm signal output by UV protection is
cancelled because the protection operation of
t
ALM(TjOH)
continues. (2)
• The protection operation is reset after the elapse of
t
ALM(TjOH)
if
V
in
is in OFF-state and
T
vj
drops below
T
jOH
-
T
jH
. (3)
※
1 Soft turn off: This means a slower than normal turn-off.
V
CC
: Supply voltage of pre-driver
V
UV
: Under voltage protection level
V
in
: Input signal voltage
V
ALM
: Alarm signal voltage
I
C
: Collector current
t
ALM(UV)
: Alarm signal hold time
t
ALM(TjOH)
: Alarm signal hold time
T
jOH
: IGBT chips over heating protection temperature level
T
jH
: Over heating protection hysteresis
3-21
Fig.3-15
T
jOH
combined protection operation (1)~(3)
the IGBT
chip surface
temperature
