Fixed 1.8V LDO with 200mA output and 4.5µA quiescent current
The TPS7A2418DBVR: Quiescent current is 4.5 µA typical, making this part suited for always-on or battery-powered circuits where the regulator's own draw must stay below the system's sleep-current budget. Maximum dropout voltage is 0.25V at the full 200mA load, so the input rail needs only 2.05V to maintain a regulated 1.8V output — useful in low-headroom designs like 3.3V-to-1.8V conversion.
PSRR across frequency for noise-sensitive analog rails
Power-supply rejection ratio is specified at 75 dB at 10 Hz, rolling off to 62 dB at 1 kHz. This means the LDO attenuates low-frequency ripple from a switching pre-regulator by a factor of roughly 5600 at 10 Hz, dropping to about 1250 at 1 kHz — relevant for powering analog front-ends or reference circuits where supply noise couples into the signal path.
Protection features and package for board integration
Built-in over-current, over-temperature, and under-voltage lockout (UVLO) protection means the LDO handles output shorts and thermal runaway without external supervisory circuitry — the UVLO holds the output off until the input rail is above the threshold, preventing brownout operation. The part is offered in a SOT-23-5 package (SC-74A, SOT-753) with surface-mount termination — the 5-pin footprint fits a standard 0.95 mm pitch layout, and the Enable pin (active-high) allows the downstream rail to be gated by a GPIO or power sequencer.