The MCP1727T-1802E/MF is a single-output LDO regulator from Microchip Technology that delivers a fixed 1.8V at up to 1.5A continuous.
60 dB PSRR at 100 Hz — what it filters and what it does not
The 60 dB PSRR at 100 Hz means the regulator attenuates 100 Hz ripple (from a rectified mains supply) by a factor of 1000 — a 100 mVpp ripple on the input becomes 100 µVpp on the output. This is relevant for analog front-ends or data converters that share a rail with a switching pre-regulator; the LDO cleans the 100-120 Hz ripple that a buck converter's output capacitor cannot fully suppress. PSRR drops with frequency — the 60 dB figure at 100 Hz does not hold at 1 MHz. For high-frequency noise above a few hundred kHz, a ferrite bead or a second-stage LC filter ahead of the LDO is still needed. The Enable and Power Good control features let the LDO sequence on and off with a microcontroller GPIO and provide a reset signal when the output is within tolerance.
Active lifecycle and compliance — no end-of-life risk for new designs
The protection set — over-temperature, short-circuit, and under-voltage lockout (UVLO) — covers the common failure modes in a power rail. The UVLO threshold prevents the output from starting until the input is high enough to keep the pass transistor in saturation, avoiding brown-out conditions on the load.
