TIDT304 October 2022
The thermal images are shown in Figure 2-3 and Figure 2-4.
The thermal images were collected under the following conditions:
The thermal simulation conditions and results are shown in Table 2-3, Figure 2-5, and Table 2-4.
FET | Package (× 2) | LMG3522R030-Q1 | 12 × 12 mm |
System Power | 3-kW PFC |
Power loss per GaN FET | 13.9 W [target RθJA = (125°C – 55°C) / 13.9 W = < 5°C/W] |
Total power loss into heat sink | 27.8 W (2 × GaN) |
PCB size | 40 mm × 37 mm |
Heat sink size | 35 mm × 26 mm × 9.2 mm |
Air Speed (m/s) |
TIM k W/mK (0.5-mm Thick) |
TA (°C) | P (W) | GaN 1 (°C) | GaN 2 (°C) | GaN 1 RθJA (C/W) | GaN2 RθJA (C/W) |
---|---|---|---|---|---|---|---|
12 | 13 | 55 | 13.9 | 97.7 | 101.8 | 3.07 | 3.37 |
Figure 2-6 shows the heat sink specification.