1.8V fixed LDO for noise-sensitive rails
The Maxim Integrated MAX8511EXK18+T is a single-output, positive fixed linear regulator delivering 1.8V at up to 120mA from a 6V maximum input. Its 90µA quiescent current keeps standby draw low, and the PSRR of 72dB at 1kHz dropping to 46dB at 100kHz gives it useful ripple rejection for powering analog or RF front-end rails where switching-regulator noise needs attenuation. The shutdown control pin lets the system disable the output when the rail is idle.
The 72dB PSRR at 1kHz and 46dB at 100kHz attenuates ripple from a preceding switching converter. The 90µA quiescent current is the regulator's own draw to maintain regulation.
Built-in over-current and over-temperature protection guard against output shorts or excessive load. The shutdown input (active-low or active-high — check the logic level in the datasheet) lets a microcontroller or system controller gate the output, reducing the quiescent draw further when the rail is not needed.