Datasheet

BD809 BD810
http://onsemi.com
4
Figure 6. Thermal Response
t, PULSE WIDTH (ms)
1.0
0.01
0.01
0.7
0.5
0.3
0.2
0.1
0.07
0.05
0.03
0.02
0.02 0.03
r(t), NORMALIZED EFFECTIVE TRANSIENT
THERMAL RESISTANCE
0.05 0.1 0.2 0.3 0.5 1.0 2.0 3.0 5.0 20 30 50 100 200 300 100
0
500
θ
JC
(t) = r(t) θ
JC
D CURVES APPLY FOR POWER
PULSE TRAIN SHOWN
READ TIME AT t
1
T
J(pk)
- T
C
= P
(pk)
θ
JC
(t)
P
(pk)
t
1
t
2
DUTY CYCLE, D = t
1
/t
2
D = 0.5
SINGLE PULSE
0.2
0.05
0.1
0.02
0.01
SINGLE
PULSE
Note 1:
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 1 is based on T
J(pk)
= 150C; T
C
is
variable depending on conditions. Second breakdown pulse
limits are valid for duty cycles to 10% provided T
J(pk)
 150C. At high case temperatures, thermal limitations
will reduce the power that can be handled to values less than
the limitations imposed by second breakdown.