6.4 Thermal Information
| THERMAL METRIC(1)(2)
|
TPS54320 |
UNIT |
| VQFN |
| 14 PINS |
| RθJA
|
Junction-to-ambient thermal resistance |
42.8 |
°C/W |
| RθJA
|
Junction-to-ambient thermal resistance(3)
|
32 |
°C/W |
| RθJC(top)
|
Junction-to-case (top) thermal resistance
|
39.4 |
°C/W |
| RθJB
|
Junction-to-board thermal resistance |
15.9 |
°C/W |
| ψJT
|
Junction-to-top characterization parameter |
0.9 |
°C/W |
| ψJB
|
Junction-to-board characterization parameter |
15.9 |
°C/W |
| RθJC(bot)
|
Junction-to-case (bottom) thermal resistance |
3.9 |
°C/W |
(2) Power rating at a specific ambient temperature TA should be determined with a junction temperature of 150°C. This is the point where distortion starts to substantially increase. Thermal management of the PCB should strive to keep the junction temperature at or below 150°C for best performance and long-term reliability. See power dissipation estimate in application section of this data sheet for more information.
(3) Test board conditions:
- 2.5 inches × 2.5 inches, 4 layers, thickness: 0.062 inch
- 2-oz. copper traces located on the top of the PCB
- 2-oz. copper ground planes on the 2 internal layers and bottom layer
- 40.010-inch thermal vias located under the device package