TPS7A45: TPS7A4533DCQR

Hi,

With input = 3.3 V, the output will be close to 3.3 V when output current is 0. As you increase the output current, the output voltage will decrease below 3.3 V. There is a finite resistance across the pass transistor, so there will be some voltage drop from input to output. See the graph on the 1st page of the datasheet and Figures 1 and 2 on page 8.

At room temp and Iout = 0.4 A, the typical dropout voltage will be 150 mV. At this operating condition, typical Vout = 3.15 V.