Philips Semiconductors
Product specification
Silicon Diffused Power Transistor
BU508AF
Zth K/W
0.5
bu508ax
BU508AD
VCESAT / V
10
1
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0.2
0.1
0.05
0.1
0.02
t
p
T
t
p
P
0.01
D
D =
0
t
T
0.001
1.0E-07
1.0E-05
1E-03
1.0E-01
1.0E+1
0.1
1
10
t / s
IC / A
Fig.7. Typical collector-emitter saturation voltage.
VCEsat = f (IC); parameter IC/IB
Fig.10. Transient thermal impedance.
Zth j-hs = f(t); parameter D = tp/T
Normalised Power Derating
PD%
BU508AD
VBESAT / V
120
110
100
90
80
70
60
50
40
30
20
10
0
1.4
1.2
1
with heatsink compound
IC = 6A
IC = 4.5A
IC = 3A
0.8
0
20
40
60
80
Ths /
100
120
140
0.6
0
1
2
3
4
C
IB / A
Fig.8. Typical base-emitter saturation voltage.
VBEsat = f (IB); parameter IC
Fig.11. Normalised power dissipation.
PD% = 100 PD/PD 25˚C = f (Ths)
VCESAT/V
BU508AD
10
1
IC = 6A
IC = 4.5A
IC = 3A
0.1
0.1
1
10
IB/A
Fig.9. Typical collector-emitter saturation voltage.
VCEsat = f (IB); parameter IC
July 1998
4
Rev 1.200
NXP [ NXP ]
