1A LDO with 54dB PSRR at 100kHz — the noise-sensitive rail workhorse
The MAX8869EUE18+ is a 1A positive linear regulator from Analog Devices, delivering an adjustable output from a 0.8V minimum (fixed 1.8V variant) with a 5.5V maximum input. It is a single-regulator LDO in the 16-TSSOP exposed-pad package, suited for post-regulation of switching supplies where the 54dB PSRR at 100kHz knocks down the switching ripple before it reaches the load. For a 1 MHz buck converter feeding this LDO, the 54dB attenuation at 100kHz means the ripple at the regulator output is roughly 0.2% of the input ripple — clean enough for analog front-ends or precision reference rails without an additional LC filter stage.
Quiescent draw and protection — what the 2 mA Iq buys you
This is not a micropower LDO for battery-always-on duty — the trade-off is the 54dB PSRR at 100kHz, which a sub-100 µA LDO cannot maintain. On-chip protection includes over-current, over-temperature, and short-circuit shutdown. The thermal limit kicks in before the junction hits the destructive region, so a momentary output short at 85°C ambient does not latch the part — it cycles until the fault clears.
Control interface and output flexibility
The Enable and Reset pins let a system sequencer or supervisor hold the output off until the input rail is stable, then release it with the Soft Start ramp. The output can be set anywhere from 0.8V to 5V with an external resistor divider — the fixed 1.8V option covers common logic and memory rails without divider components. Output configuration is positive, single regulator — no dual-output or inverting topology here. The adjustable range from 0.8V to 5V covers the majority of core, I/O, and analog supply voltages in a mixed-signal system.
Package thermal reality — the exposed pad is not optional
The 16-TSSOP with exposed pad (EP) is the only package option. The 4.40 mm body width gives a reasonable copper area under the part for a 2-layer board.
Active production, ROHS3, and sourcing posture
Analog Devices lists the MAX8869EUE18+ as Active, with ROHS3 compliance.