For this design example, the 3.3-V output version (TPS7A2133) is selected. A nominal 3.6-V input supply is assumed. Use a minimum 1.0-μF input capacitor to minimize the effect of resistance and inductance between the 3.6-V source and the LDO input. A minimum 1.0-μF output capacitor is also used for stability and good load transient response. The dropout voltage (V_DO) is less than 150 mV maximum at a 3.3-V output voltage and 500-mA output current, so there are no dropout issues with a minimum input voltage of 3.5 V and a maximum output current of 400 mA.

With an ambient temperature of 85°C, an input voltage of 3.6 V and an output current of 400 mA, the die temperature is 0.3 V × 0.4 A × 197.1°C/W + 85°C = 108.7°C.