SLVSAB1G June 2011 – March 2020 TPS7A63-Q1 , TPS7A6401-Q1
PRODUCTION DATA.
If IOUT = 100 mA, VOUT = 5 V, VIN = 14 V, IQUIESCENT = 250 µA, and RθJA= 50°C/W, the continuous power dissipated in the device is 0.9 W. The rise in junction temperature due to power dissipation is 45°C. For a maximum junction temperature of 150°C, the maximum ambient air temperature at which the device can operate is 105°C.
For adequate heat dissipation, TI recommends soldering the thermal pad (exposed heat sink) to the thermal land pad on the PCB. Doing this provides a heat conduction path from the die to the PCB and reduces overall package thermal resistance. Power derating curves for the TPS7A63-Q1 and TPS7A6401-Q1 PWP package and TPS7A6333-Q1 DRK are comparable; see Figure 35.
For optimum thermal performance, TI recommends using a high-K PCB with thermal vias between the ground plane and solder pad or thermal land pad; see Figure 36 (a) and (b). Further, use a thicker ground plane and a thermal land pad with a larger surface area to inprove considerably the heat-spreading capabilities of a PCB. For a two-layer PCB, a bat wing layout can enhance the heat-spreading capabilities.
Keeping other factors constant, surface area of the thermal land pad contributes to heat dissipation only to a certain extent.