Heat Transfer of DE-Series MOSFETs

Table 1

Measured values to calculate power dissipation.

Drain current ID (rms) (A)	On-state resistance RDS (on)     (Ω)	First power dissipation PDA     (W)	Ambient temperature tA (°C)	Heatsink temperature tS (°C)	Drain source voltage VDS (V)	Second power dissipation PDB (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%