800mA adjustable LDO — dropout and ripple rejection
The Texas Instruments LM1117S-ADJ/NOPB is a positive adjustable LDO regulator delivering 800mA output. Its maximum dropout of 1.2V at full load means the input rail needs to stay at least 1.2V above the set output voltage to maintain regulation — a common gotcha when squeezing a 3.3V rail from a 5V supply with margin. The 75dB PSRR at 120Hz gives good line-frequency ripple rejection, useful when this LDO sits after a rectifier and bulk capacitor in a linear supply chain.
Output range and protection
The part includes over-current and over-temperature protection, so it folds back gracefully under a short or thermal runaway.
Housed in a TO-263-3 DDPAK (D²Pak) surface-mount package with an exposed tab. The /NOPB suffix confirms ROHS3 compliance and lead-free assembly.
It is a current-production TI device, so new designs can commit the BOM line without near-term obsolescence risk.