MJB5742T4G
http://onsemi.com
5
SAFE OPERATING AREA INFORMATION
FORWARD 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.
REVERSE BIAS
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.
I
C
, COLLECTOR CURRENT (AMPS)
V
CE
, COLLECTOR-EMITTER VOLTAGE (VOLTS)
V
CE
, COLLECTOR-EMITTER VOLTAGE (VOLTS)
Figure 6. Forward Bias Safe Operating Area
Figure 7. Reverse Bias Safe Operating Area
16
14
12
8
0
2
4
10
100 200 300 5000 400
16
5
10
8
1
0.02
100
I
C
, COLLECTOR CURRENT (AMPS)
0.1
10 20 200 400
3
0.5
50
0.3
0.05
dc
1ms
100 ms
MJB5742
V
BE(off)
≤ 5 V
T
J
= 100°C
6
CURVES APPLY BELOW RATED V
CEO
10 ms
5ms
BONDING WIRE LIMIT
THERMAL LIMIT
(SINGLE PULSE)
SECOND BREAKDOWN LIMIT
t, TIME (s)μ
t, TIME (s)μ
I
C
, COLLECTOR CURRENT (AMPS)
0.5 0.7 1 2 10
7
5
2
1
0.7
0.2
0.3 5
0.5
10
3
3
0.3
0.2 7
I
C
, COLLECTOR CURRENT (AMPS)
0.5 0.7 1 2 10
0.7
0.5
0.2
0.1
0.07
0.02
0.3
Figure 8. Turn−On Time
5
0.05
1
Figure 9. Turn−Off Time
3
V
CC
= 250 V
I
B1
= I
B2
I
C
/I
B
= 20
t
s
t
r
t
f
t
d
V
CC
= 250 V
I
B1
= I
B2
I
C
/I
B
= 20
0.3
0.03
0.2 7
RESISTIVE SWITCHING PERFORMANCE
