Table 1:
Measured values to calculate power dissipation.
Drain current
I
D
(rms)
(A)
On-state resistance
R
DS
(on)
(Ω)
First power dissipation
P
D
A
(W)
Ambient temperature
t
A
(°C)
Heatsink temperature
t
S
(°C)
Drain source voltage
V
DS
(V)
Second power dissipation
P
D
B
(W)
Percentage difference (%)
Changing ambient temperature
1.00
0.40
0.40
25.4
25.8
0.40
0.40
0%
2.00
0.65
2.60
29.3
31.9
1.37
2.74
−5%
3.00
0.88
7.90
36.5
44.4
2.79
8.38
6%
4.00
1.27
20.30
46.8
67.1
5.51
22.03
8%
Constant ambient temperature
1.00
1.34
1.34
24.6
25.9
0.40
0.40
−234%
2.00
1.83
7.30
24.6
31.9
1.37
2.74
167%
3.00
2.16
19.41
24.6
44.0
2.79
8.38
132%
4.00
2.62
41.89
24.6
66.5
5.51
22.03
90%