500 mA LDO with a 2.5 V fixed rail
The MCP1725-2502E/SN is a single-output positive LDO regulator from Microchip Technology, delivering a fixed 2.5 V at up to 500 mA from a 6 V maximum input rail.
Dropout and quiescent — where the margin lives
Quiescent current is 220 µA typical; this is the regulator's own draw that always flows from input to ground, so it sets the floor for battery-powered standby consumption. Power-supply rejection is 60 dB at 100 Hz — ripple at the input at that frequency is attenuated by a factor of 1000 before it reaches the output, which matters when the LDO follows a switching pre-regulator.
Protection and control for unattended gear
On-chip protection includes over-temperature shutdown, short-circuit current limiting, and under-voltage lockout (UVLO) — the UVLO prevents the pass element from operating in its linear region when the input rail is too low to regulate. Enable and Power Good control features let the system sequence the 2.5 V rail: the Enable pin shuts the output off to under 1 µA, and the Power Good open-drain output asserts when the output reaches about 92% of its nominal value.