NXP Semiconductors
BC639; BCP56; BCX56
80 V, 1 A NPN medium power transistors
6. Thermal characteristics
Table 7.
Symbol
R
th(j-a)
Thermal characteristics
Parameter
thermal resistance from
junction to ambient
BC639
BCP56
BCX56
Conditions
in free air
Min
Typ
Max
Unit
-
-
-
-
-
-
-
-
-
-
-
-
150
195
130
250
145
100
K/W
K/W
K/W
K/W
K/W
K/W
R
th(j-sp)
thermal resistance from
junction to solder point
BC639
BCP56
BCX56
-
-
-
-
-
-
40
17
30
K/W
K/W
K/W
[1]
[2]
[3]
Device mounted on an FR4 PCB, single-sided copper, tin-plated and standard footprint.
Device mounted on an FR4 PCB, single-sided copper, tin-plated, mounting pad for collector 1 cm
2
.
Device mounted on an FR4 PCB, single-sided copper, tin-plated, mounting pad for collector 6 cm
2
.
10
3
Z
th(j-a)
(K/W)
10
2
006aaa088
duty cycle =
1
0.75
0.5
0.33
0.2
0.1
10
0.05
0.02
0.01
1
10
−5
0
10
−4
10
−3
10
−2
10
−1
1
10
10
2
t
p
(s)
10
3
FR4 PCB, standard footprint
Fig 4. Transient thermal impedance from junction to ambient as a function of pulse duration for SOT54;
typical values
BC639_BCP56_BCX56_8
© NXP B.V. 2007. All rights reserved.
Product data sheet
Rev. 08 — 22 June 2007
6 of 15
PHILIPS [ NXP SEMICONDUCTORS ]
