评估IC的结温时,选择不同的热阻,得到了不同的结温。 请问该选择哪一个参数才是正确的?

| Measured temp | Measured temp | Estimated | ||
| Ambient | °C | 32.3 | 30.85 | 45 |
| Cabinet inside | 37.95 | 38.6 | 52.75 | |
| M04 inside | °C | 46 | 49.25 | 65 |
| Vinput | V | 5.5 | ||
| PWR_Drive | V | 4.75 | ||
| Iout | A | 0.858 | ||
| Pin | W | 4.774 | ||
| Pout | W | 4.0755 | ||
| Ploss | W | 0.6985 | ||
| Top Case | °C | 90.5 | 92.9 | 108.65 |
| IC air temp | °C | 70.95 | 86.7 | |
| PCB Copper | °C | 83.45 | ||
| Pin | °C | 87.45 | 103.2 | |
| Rjc | °C/W | 5.1 | ||
| Tj=Tcase+Rjc*P | °C | 106.76 | ||
| Rjc | °C/W | 31.5 | ||
| Tj=Tcase+Rjc*P | °C | 130.7 | ||
| Rja | °C/W | 50 | ||
| Tj=Tcase+Rjc*P | °C | 121.625 |
