MT6M15962a
5. タイミングチャート
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5.4 Over current protection (OC) operation
• When
I
C
exceeds the over current protection level
I
OC
, an alarm signal is output after the elapse of
t
dOC
, and the IGBT is turned off softly
※
1
. (1)
• The protection operation continues during the period of
t
ALM(OC)
even if
V
in
is in OFF-state, and
resumes to normal operation after the elapse of
t
ALM(OC)
if
V
in
becomes OFF-state. (2)
• The protection operation continues if
V
in
is in ON-state after the elapse of
t
ALM(OC)
, and resumes to
normal operation if the
V
in
becomes OFF-state. (3)
• If
V
in
is in OFF-state before the elapse of
t
dOC
after
I
C
exceeds
I
OC
, the protection operation is not
activated and the IGBT is turned off normally
※
2
. (4)
• Even if
I
C
exceeds
I
OC
when
V
in
is in ON-state, if
V
in
becomes OFF-state before the elapse of
t
dOC
, the
protection operation is not activated and the IGBT is turned-off normally. (5)
• Even if the protection operating duration is sufficiently longer than
t
ALM(OC)
, the alarm signal is output
only once.
※
1 Soft turn off: This means a slower than normal turn-off.
※
2 Normal turn off: This means a normal turn-off operation.
3-17
Fig.3-11 OC protection operation
V
in
: Input signal voltage
V
ALM
: Alarm signal voltage
I
C
: Collector current
I
OC
: Over current protection level
t
ALM(OC)
: Alarm signal hold time
t
dOC
: Over current protection delay time
