65V input LDO with watchdog and reset
The MAX5023MASA+ from Analog Devices is a high-voltage linear regulator delivering a fixed 5V output at up to 150mA. Its 65V maximum input rating makes it a natural fit for 24V and 48V industrial rails where a downstream 5V logic or sensor supply is needed without a separate DC-DC stage. The part integrates Enable, Hold, Reset, and Watchdog control features — the watchdog alone saves an external supervisor IC in applications where the microcontroller must be monitored for lock-up.
Dropout, quiescent current, and protection
Quiescent current is 140 µA typical, low enough to keep the regulator alive on a battery-backed rail without draining the reserve during standby. Protection covers over-temperature, reverse polarity, and short-circuit — the reverse-polarity clamp is unusual in a linear regulator and saves an external series diode when the input could be mis-wired.
PSRR and noise rejection in the audio band
PSRR is specified at 54dB at 100Hz, meaning ripple on the input at mains frequency and its harmonics is attenuated by a factor of roughly 500 before reaching the output — relevant when the regulator is powered from a rectified AC source or a switching pre-regulator with 100/120Hz ripple.