800 mA output, 1.2 V dropout — thermal headroom matters
This is a single-output, positive fixed LDO rated for 800 mA continuous output current. The maximum dropout voltage is 1.2 V at 800 mA load, which means the input rail must stay at least 1.2 V above 2.85 V (i.e., above 4.05 V) to maintain regulation at full current. For a 2.85 V rail powering analog or low-voltage digital loads, the dropout figure sets the minimum input voltage and the thermal budget in the TO-220-3 package.
The power supply rejection ratio is 75 dB at 120 Hz, which is the typical ripple frequency from a full-wave rectified mains supply. This makes the LM1117T-2.85/NOPB a reasonable choice for post-regulation after a bulk capacitor, where 120 Hz ripple needs attenuation before feeding sensitive loads like analog front-ends or low-noise bias circuits. The fixed 2.85 V output is less common than 3.3 V or 1.8 V, so verify the rail voltage matches the load requirement exactly.
TO-220-3 through-hole — board-level integration
The through-hole mounting requires a drilled PCB and wave or hand soldering, which is typical for power regulators that benefit from the tab's thermal path to a heatsink or copper plane. Protection features include over-current and over-temperature shutdown.