Feb.1999
MITSUBISHI SEMICONDUCTOR
HIGH-SPEED SWITCHING THYRISTOR
CR3JM
LOW POWER, STROBE USE
NON-INSULATED TYPE, GLASS PASSIVATION TYPE
CR3JM
APPLICATION
Automatic strobe flasher
V
1. Refer to sections 1, 2 on STROBE FLASHER APPLICATION.
Parameter
Average on-state current
Repetitive peak on-state current
V
1
Peak gate power dissipation
Average gate power dissipation
Peak gate forward voltage
Peak gate reverse voltage
Peak gate forward current
Junction temperature
Storage temperature
Weight
Symbol
I
T (AV)
I
TRM
P
GM
P
G (AV)
V
FGM
V
RGM
I
FGM
T
j
T
stg
--
Conditions
Commercial frequency, sine half wave, 180
conduction, T
a
=37
C
C
M
=1800
F with discharge current
Typical value
Unit
A
A
W
W
V
V
A
C
C
g
Ratings
0.8
240
3.0
0.3
6
6
1
40 ~ +125
40 ~ +125
2.0
I
T (AV)
........................................................................ 0.8A
V
DRM
....................................................................... 400V
I
GT
..........................................................................50mA
Symbol
V
RRM
V
RSM
V
DRM
V
DSM
Parameter
Repetitive peak reverse voltage
Non-repetitive peak reverse voltage
Repetitive peak off-state voltage
Non-repetitive peak off-state voltage
Voltage class
Unit
V
V
V
V
8
400
480
400
480
MAXIMUM RATINGS
TYPE
NAME
VOLTAGE
CLASS
10.5 MAX
4.5
2.5
2.5
0.8
1.0
3.60.2
1.3
0.5
2.6
12.5 MIN
3.8 MAX
16 MAX
7.0
3.20.2
4.5
2 3
1
4
Measurement point of
case temperature
OUTLINE DRAWING
Dimensions
in mm
TO-220
2 4
1
3
1
2
3
4
CATHODE
ANODE
GATE
ANODE
Feb.1999
C
C
22
10k
1k
L
V
CM
C
M
10
0.1
+
-
15k
0.1
I
T
T.U.T
A
3
V
3 The circuit between A-B is a substitute for Xenon flash tube.
B
MITSUBISHI SEMICONDUCTOR
HIGH-SPEED SWITCHING THYRISTOR
CR3JM
LOW POWER, STROBE USE
NON-INSULATED TYPE, GLASS PASSIVATION TYPE
STROBE FLASHER APPLICATION
Be sure to remember the following points when designing series
type automatic strobe flashers using the CR3JM or CR3AMZ.
1. Rated repetitive peak on-state current I
TRM
The figure shows a turn-off characteristic test circuit.
When a repetitive discharge current passes to the thyristor
(TUT) through the load from the charged main capacitor (C
M
),
the limiting value for the on-state peak current the thyristor can
withstand is the rated repetitive peak on-state current.
To ensure the current fed into the thyristor will not exceed this
rated value, it is essential to select the appropriate main capaci-
tor charging voltage V
CM
, the load (Xenon lamp) resistance and
the anode reactor L described below.
2. Main capacitor C
M
In addition to its effect on the peak on-state current value, the
capacitance of the main capacitor is an important factor deter-
mining the temperature rise of the thyristor junction. When the
capacitance of the main capacitor becomes large, the dis-
charge-time constant becomes great also, the temperature rise
at the thyristor junction will be very serious and the commutating
capability of the thyristor will decrease. When the device is
turned off, damage may also be caused by the reverse voltage
applied to the thyristor resulting in thermal run away.
3. Commutating Capacitor C
C
The capacitance values of the commutating Capacitor (C
C
) re-
quired for turning the thyristor off can be obtained from the fol-
lowing equation since the electric charge stored in this capacitor
and the electric charge released during commutation are the
same.
CC
i
T
t
q
V
CC
i
2T
2V
CC
(di
T
/dt)
C
+
+
C
C
(
F)
Where
i
T
: On-state current (A) immediately before turning off
t
q
: Pulse turn-off time of the thyristor (
s)
V
CC
: C
C
charging voltage (V)
(di
T
/dt)
C
: Rate of on-state current drop during commutation (A/
s)
C
C
: Loss component due to the impedance of the commutat-
ing circuit.
In real conditions, however, the turn-off time will vary consider-
ably depending on the temperature of the junction, and the gate
reverse bias conditions during turn-off. It is necessary, therefore,
to check the actual C
C
value and to adapt the settings (circuit
conditions).
The commutating characteristics graph shown in the figure re-
lates to general circuit conditions.
4.
Anode reactor L
When the thyristor is turned on, the anode reactor L is used to
control the rise of the discharge current from the main capacitor
and the commutating circuit current in the commutating mode,
respectively. The anode reactor L is suitable for use within the
range of 20~100
H (air core).
With this anode reactor inserted, the voltage during commuta-
tion may rise and the thyristor may lead to withstand voltage de-
terioration so that it is necessary to connect the 1~3A class rec-
tifier diode in anti-parallel for protection, i.e., in the opposite di-
rection to the flow of the discharge current.
Fig 1. TEST CIRCUIT FOR COMMUTATING CAPACITOR
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