What this 1.8V 800mA LDO delivers on the board
The LD1117S18CTR is a single-output, positive fixed LDO from STMicroelectronics, delivering 1.8V at up to 800mA continuous output current. Maximum dropout is 1.3V at full load, so the input rail must stay above 3.1V to maintain regulation.
Dropout, quiescent current, and protection
Over-current and over-temperature protection are built in, so the regulator folds back safely under a short or thermal runaway. Input voltage range extends to 15V max, giving headroom for 5V or 12V intermediate rails.