MJE5740_06 Datasheet, PDF (5/6 Pages) ON Semiconductor – NPN Silicon Power Darlington Transistors 8 AMPERES 300−400 VOLTS 80 WATTS

MJE5740, MJE5742
SAFE OPERATING AREA INFORMATION
FORWARD BIAS
REVERSE BIAS
There are two limitations on the power handling ability of
a transistor: average junction temperature and second
breakdown. Safe operating area curves indicate I_C − V_CE
limits of the transistor that must be observed for reliable
operation; i.e., the transistor must not be subjected to greater
dissipation than the curves indicate.
The data of Figure 6 is based on T_C = 25_C; T_J(pk) is
variable depending on power level. Second breakdown
pulse limits are valid for duty cycles to 10% but must be
derated when T_C ≥ 25_C. Second breakdown limitations do
not derate the same as thermal limitations. Allowable
current at the voltages shown on Figure 6 may be found at
any case temperature by using the appropriate curve on
Figure 1.
For inductive loads, high voltage and high current must be
sustained simultaneously during turn−off, in most cases,
with the base to emitter junction reverse biased. Under these
conditions the collector voltage must be held to a safe level
at or below a specific value of collector current. This can be
accomplished by several means such as active clamping, RC
snubbing, load line shaping, etc. The safe level for these
devices is specified as Reverse Bias Safe Operating Area
and represents the voltage−current condition allowable
during reverse biased turnoff. This rating is verified under
clamped conditions so that the device is never subjected to
an avalanche mode. Figure 7 gives the complete RBSOA
characteristics.
The Safe Operating Area figures shown in Figures 6 and 7 are specified ratings for these devices under the test conditions shown.
16
10
8
100 ms
3
10 ms
5 ms
1
0.5
0.3
BONDING WIRE LIMIT
1 ms
THERMAL LIMIT
dc
(SINGLE PULSE)
0.1
SECOND BREAKDOWN LIMIT
0.05 CURVES APPLY BELOW RATED V_CEO
MJE5742
MJE5740
0.02
5
10
20
50
100
200 400
V_CE, COLLECTOR−EMITTER VOLTAGE (VOLTS)
Figure 6. Forward Bias Safe Operating Area
16
14
12
10
8
6
V_BE(off) ≤ 5 V
T_J = 100°C
4
2
MJE5742
MJE5740
0
0
100
200
300
400
500
V_CE, COLLECTOR−EMITTER VOLTAGE (VOLTS)
Figure 7. Reverse Bias Safe Operating Area
RESISTIVE SWITCHING PERFORMANCE
1
t_r
0.7
0.5
0.3
0.2
t_d
0.1
0.07
0.05
V_CC = 250 V
I_B1 = I_B2
I_C/I_B = 20
0.03
0.02
0.2 0.3
0.5 0.7 1
2 3 5 7 10
I_C, COLLECTOR CURRENT (AMPS)
Figure 8. Turn−On Time
10
7
t_s
5
3
2
1
0.7
0.5
0.3
0.2
0.2 0.3
V_CC = 250 V
I_B1 = I_B2
t_f
I_C/I_B = 20
0.5 0.7 1
2 3 5 7 10
I_C, COLLECTOR CURRENT (AMPS)
Figure 9. Turn−Off Time
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