6.4 Thermal Information
THERMAL METRIC(1) |
TPSM84209 |
UNIT |
RKH (QFN) |
9 PINS |
RθJA |
Junction-to-ambient thermal resistance(2) |
32.7 |
°C/W |
ψJT |
Junction-to-top characterization parameter(3) |
2.2 |
°C/W |
ψJB |
Junction-to-board characterization parameter(4) |
17 |
°C/W |
(1) For more information about traditional and new thermal metrics, see the
Semiconductor and IC Package Thermal Metrics application report,
SPRA953.
(2) The junction-to-ambient thermal resistance, RθJA, applies to devices soldered directly to a 63 mm × 50 mm, 4-layer PCB with 2 oz. copper and natural convection cooling. Additional airflow reduces RθJA.
(3) The junction-to-top characterization parameter, ψJT, estimates the junction temperature, TJ, of a device in a real system, using a procedure described in JESD51-2A (section 6 and 7). TJ = ψJT × Pdis + TT; where Pdis is the power dissipated in the device and TT is the temperature of the top of the device.
(4) The junction-to-board characterization parameter, ψJB, estimates the junction temperature, TJ, of a device in a real system, using a procedure described in JESD51-2A (sections 6 and 7). TJ = ψJB × Pdis + TB; where Pdis is the power dissipated in the device and TB is the temperature of the board 1mm from the device.