85 dB PSRR across 100 Hz to 10 MHz — the ripple rejection envelope
The MIC94310-4YM5-TR from Microchip Technology is a single-output, positive fixed LDO in the Ripple Blocker™ series. Its headline spec is the PSRR curve: 85 dB at 100 Hz rolling off to 50 dB at 10 MHz — that bandwidth covers switching-regulator ripple and its harmonics, not just the fundamental. Rated for 200 mA output with a maximum dropout of 100 mV at full load, the headroom between input rail and the 1.2 V fixed output needs to stay above that 100 mV across load and temperature to keep regulation.
Industrial temperature grade and enable control
Operating from -40°C to 125°C, this LDO suits engine-bay or outdoor enclosure deployment where the ambient temperature pushes past the commercial 85°C ceiling. The enable pin lets a system sequencer or supervisor gate the output — useful in multi-rail power-up schemes where the 1.2 V rail must not rise before the core supply. Quiescent current is 250 µA typical; the 200 mA output is internally current-limited and thermally protected, so a sustained overload or short on the output shuts the part down rather than exceeding the junction temperature.