Datasheet

BC856ALT1G Series
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5
Figure 13. Thermal Response
t, TIME (ms)
1.0
r(t), TRANSIENT THERMAL
2.0 5.01.00.50.20.1
RESISTANCE (NORMALIZED)
0.7
0.5
0.3
0.2
0.1
0.07
0.05
0.03
0.02
0.01
20 5010 200 500100 1.0k 2.0k 5.0k 10k
Figure 14. Active Region Safe Operating Area
V
CE
, COLLECTOR-EMITTER VOLTAGE (V)
-200
-1.0
I
C
, COLLECTOR CURRENT (mA)
T
A
= 25°C
D = 0.5
0.2
0.1
0.05
SINGLE PULSE
SINGLE PULSE
BONDING WIRE LIMIT
THERMAL LIMIT
SECOND BREAKDOWN LIMIT
3 ms
T
J
= 25°C
Z
q
JC
(t) = r(t) R
q
JC
R
q
JC
= 83.3°C/W MAX
Z
q
JA
(t) = r(t) R
q
JA
R
q
JA
= 200°C/W MAX
D CURVES APPLY FOR POWER
PULSE TRAIN SHOWN
READ TIME AT t
1
T
J(pk)
- T
C
= P
(pk)
R
q
JC
(t)
t
1
t
2
P
(pk)
DUTY CYCLE, D = t
1
/t
2
-100
-50
-10
-5.0
-2.0
-5.0 -10 -30 -45 -65 -100
1 s
BC558, BC559
BC557
BC556
The safe operating area curves indicate I
C
−V
CE
limits
of
the transistor that must be observed for reliable operatio
n.
Collector load lines for specific circuits must fall below th
e
limits indicated by the applicable curve.
The data of Figure 14 is based upon T
J(pk)
= 150°C; T
C
or
T
A
is variable depending upon conditions. Pulse curves a
re
valid for duty cycles to 10% provided T
J(pk)
≤ 150°C. T
J(p
k)
may be calculated from the data in Figure 13. At high case
or
ambient temperatures, thermal limitations will reduce th
e
power that can be handled to values less than the limitatio
ns
imposed by the secondary breakdown.