1.0
0.7
0.5
D = 0.5
0.2
0.3
0.2
0.1
0.05
P
(pk)
0.1
0.07
0.05
R
R
= r(t) R
θ
θ
θ
JC(t)
= 8.34
JC
C/W MAX
°
JC
D CURVES APPLY FOR POWER
PULSE TRAIN SHOWN
READ TIME AT t
0.02
0.01
t
1
0.03
0.02
t
2
1
(pk)
0 (SINGLE PULSE)
T
– T = P
R
J(pk)
C
θ
JC(t)
100
DUTY CYCLE, D = t /t
1 2
0.01
0.02
0.05
0.1
0.2
0.5
1.0
2.0
t, TIME (ms)
5.0
10
20
50
200
Figure 4. Thermal Response
10
There are two limitations on the power handling ability of a
transistor: average junction temperature and second break-
100
500
µs
5.0
1.0 ms
µs
2.0
down. Safe operating area curves indicate I – V
limits of
C
CE
dc
the transistor that must be observed for reliable operation,
i.e., the transistor must not be subjected to greater dissipa-
tion than the curves indicate.
1.0
0.5
T
= 150°C
J
5.0 ms
BONDING WIRE LIMITED
THERMALLY LIMITED @ T = 25°C
C
(SINGLE PULSE)
The data of Figure 5 is based on T
= 150 C: T is
C
J(pk)
variable depending on conditions. Second breakdown pulse
limits are valid for duty cycles to 10% provided T
0.1
0.05
J(pk)
may be calculated from the data in Fig-
SECOND BREAKDOWN LIMITED
150 C, T
J(pk)
CURVES APPLY BELOW RATED V
CEO
ure 4. At high case temperatures, thermal limitations will re-
duce the power that can be handled to values less than the
limitations imposed by second breakdown.
BD789 (NPN) BD790 (PNP)
BD791 (NPN) BD792 (PNP)
0.02
0.01
1.0
2.0 3.0
5.0 7.0 10
20
30
50 70 100
V
, COLLECTOR–EMITTER VOLTAGE (VOLTS)
CE
Figure 5. Active Region Safe Operating Area
2000
1000
200
T
= 25°C
T
= 25°C
J
J
V
I
= 30 V
/I = 10
CC
100
700
500
C B
B1 B2
C
ib
I
= I
t
s
70
50
300
200
100
70
50
C
30
20
ob
t
f
BD789, 791 (NPN)
BD790, 792 (PNP)
BD789, 791 (NPN)
BD790, 792 (PNP)
30
20
10
1.0
2.0
3.0
5.0 7.0
10 20
30
50 70 100
0.04 0.06
0.1
0.2
0.4
0.6
1.0
2.0
4.0
V
, REVERSE VOLTAGE (VOLTS)
R
I
, COLLECTOR CURRENT (AMP)
C
Figure 7. Capacitance
Figure 6. Turn–Off Time
3
Motorola Bipolar Power Transistor Device Data