500 mA LDO with 1.2 V fixed output
The MCP1725-1202E/SN is a single-output positive LDO regulator from Microchip Technology, delivering a fixed 1.2 V at up to 500 mA from a maximum 6 V input rail. Maximum dropout is 0.35 V at the full 500 mA load — the input-to-output headroom must stay above this across the operating range to maintain regulation. Quiescent current is 220 µA typical; in shutdown the Enable pin pulls the regulator into a low-power state, making it viable for battery-powered equipment that sleeps between duty cycles.
PSRR and noise rejection at 100 Hz
Power supply rejection ratio is 60 dB at 100 Hz — this is the ripple attenuation from a full-wave rectified mains supply or a 50/60 Hz switching pre-regulator. A 60 dB rejection means the output ripple is 1/1000th of the input ripple at that frequency. For a 100 mVpp input ripple at 100 Hz, the output sees roughly 0.1 mVpp — clean enough to bias an analog front-end or a precision reference without additional post-filtering.
Temperature grade and protection
An outdoor sensor node or an engine-bay ECU that sees 105°C ambient still has margin before the thermal shutdown threshold. On-chip protection includes over-temperature shutdown, short-circuit current limiting, and under-voltage lockout (UVLO) that holds the output off until the input rail reaches the minimum operating voltage.
The supplier device package is 8-SOIC, matching the case code. Supplied in tube packaging; the surface-mount profile follows the standard JEDEC MSL-1 reflow curve for 8-SOIC, no bake required before assembly if the seal is intact.