Diodes BC846BLP4 - Manual (Page 3)

BC846BLP4
Document number: DS35751 Rev. 2 - 2
3 of 7
www.diodes.com
July 2012
© Diodes Incorporated
BC846BLP4
Thermal Characteristics
0.000001 0.0001 0.01 1 100 10,000
0.001
0.01
0.1
1
r(t
),
T
R
ANS
IEN
T
T
H
E
R
MA
L
R
ES
IS
T
AN
C
E
t1, PULSE DURATION TIME (sec)
Fig. 1 Transient Thermal Resistance
R (t) = r(t) * R
R = 272°C/W
Duty Cycle, D = t1/ t2
θ θ
θ
JA JA
JA
D = 0.5
D = 0.7
D = 0.9
D = 0.3
D = 0.1
D = 0.05
D = 0.02
D = 0.01
D = 0.005
D = Single Pulse
1,000
1E-06 0.0001 0.01 1 100 10,000
100
10
1
0.1
t1, PULSE DURATION TIME (sec)
Fig. 2 Single Pulse Maximum Power Dissipation
P
,
P
E
AK
T
R
AN
SI
EN
T
P
O
IW
E
R
(W
)
(P
K
)
Single Pulse
R
= 272 C/W
R = r * R
T - T = P * R
θ
θ
θ
θ
JA
JA(t) (t) JA
J A JA(t)
°
0 50 100 150 200
0
P
,
P
O
WE
R
DISS
IP
A
T
IO
N
(W
)
D
0.1
0.2
0.3
0.4
0.5
T , AMBIENT TEMPERATURE (°C)
Fig. 3 Power Dissipation vs. Ambient Temperature
A
R = 272 C/W θJA
°