Fixed 2.5V rail for precision analog and digital loads
The MIC5245-2.5YM5-TR is a single-output positive LDO regulator from Microchip Technology that delivers a fixed 2.5V output at up to 150 mA. Packaged in a SOT-23-5 (SC-74A / SOT-753) surface-mount footprint, this regulator is suited for space-constrained PCBs where a clean 2.5V supply is needed for analog front-ends, reference circuits, or low-voltage digital cores.
PSRR and quiescent current: analog supply purity vs standby draw
Power-supply rejection ratio is 50 dB at 120 Hz — this is the ripple-rejection figure at the fundamental of a full-wave rectified mains supply. For a 2.5V rail feeding an op-amp or ADC reference, 50 dB of rejection at 120 Hz attenuates a 100 mVpp ripple to roughly 0.3 mVpp, keeping the supply clean enough for 12-bit precision without additional post-filtering. Quiescent current is 150 µA typical — this is the current the regulator itself consumes to maintain regulation, independent of the load. In an always-on sensor node drawing a few mA, the 150 µA Iq sets the standby power floor; at 2.5V output that is 375 µW of overhead before any load current flows. The enable pin allows the output to be shut down externally, dropping the quiescent current to near zero in sleep modes.
Protection features and compliance
On-chip protection includes over-current limiting, thermal shutdown, and under-voltage lockout (UVLO). These prevent the regulator from exceeding its safe operating area during a fault or start-up sequence without external clamp diodes or foldback circuits.