Datasheet

PMBT3904YS_1 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 01 — 12 May 2009 4 of 12
NXP Semiconductors
PMBT3904YS
40 V, 200 mA NPN/NPN general-purpose double transistor
6. Thermal characteristics
[1] Device mounted on an FR4 PCB, single-sided copper, tin-plated and standard footprint.
Table 7. Thermal characteristics
Symbol Parameter Conditions Min Typ Max Unit
Per transistor
R
th(j-a)
thermal resistance from
junction to ambient
in free air
[1]
- - 543 K/W
R
th(j-sp)
thermal resistance from
junction to solder point
- - 290 K/W
Per device
R
th(j-a)
thermal resistance from
junction to ambient
in free air
[1]
- - 357 K/W
FR4 PCB, standard footprint
Fig 2. Per transistor: Transient thermal impedance from junction to ambient as a function of pulse duration;
typical values
006aab114
10
−5
1010
−2
10
−4
10
2
10
−1
t
p
(s)
10
−3
10
3
1
10
2
10
10
3
Z
th(j-a)
(K/W)
1
δ = 1
0.33
0.01
0.02
0.05
0.5
0.1
0.2
0
0.75