1.0
0.7
0.5 D = 0.5
0.2
0.3
0.2
0.1
0.1
0.07
0.05
0.03
0.02
0.01
0.1 0.2
0.05
0.5
BC517
SINGLE PULSE
SINGLE PULSE
ZθJC(t) = r(t) • RθJC TJ(pk) – TC = P(pk) ZθJC(t)
ZθJA(t) = r(t) • RθJA TJ(pk) – TA = P(pk) ZθJA(t)
1.0 2.0
5.0 10
20
50 100 200
t, TIME (ms)
Figure 12. Thermal Response
500 1.0 k 2.0 k
5.0 k 10 k
1.0 k
700
500
300
TA = 25°C
200
1.0 ms
TC = 25°C 100 µs
1.0 s
FIGURE A
tP
PP
PP
100
70
50
30
CURRENT LIMIT
20
THERMAL LIMIT
SECOND BREAKDOWN LIMIT
10
0.4 0.6 1.0 2.0
4.0 6.0 10
20
40
VCE, COLLECTOR–EMITTER VOLTAGE (VOLTS)
Figure 13. Active Region Safe Operating Area
t1
1/f
+ + DUTY CYCLE
t1 f
t1
tP
PEAK PULSE POWER = PP
Design Note: Use of Transient Thermal Resistance Data
Motorola Small–Signal Transistors, FETs and Diodes Device Data
5