300 mA LDO with 4.2 V fixed output
The TPS7A2042PDBVR is a single-output positive LDO from Texas Instruments, delivering 300 mA at a fixed 4.2 V. The maximum dropout is just 145 mV at full load, meaning the input rail needs to stay above 4.345 V to maintain regulation across the entire load range. Quiescent current is 15 µA typical, which keeps the regulator's own draw low enough for always-on or battery-backed rails where every microamp matters.
PSRR profile and noise rejection
Power-supply rejection ratio runs 65 dB at 100 Hz and rolls to 40 dB at 1 MHz. This means low-frequency ripple from a mains-derived rail gets attenuated by a factor of ~1800, while higher-frequency switching noise above a few hundred kHz sees less than 100× rejection. For a clean analog supply, you'll want a post-filter if the upstream switcher operates above 500 kHz.
Package, temperature grade, and control
Housed in a 5-pin SOT-23-5 (SC-74A), the part is surface-mount with a standard 0.95 mm pitch footprint. Operating junction temperature spans -40°C to 125°C, covering industrial and automotive under-hood environments. Enable and soft-start control pins are included; the soft-start limits inrush current during output ramp-up, which is useful when the load has large decoupling caps. Protection features cover over-current, over-temperature, and under-voltage lockout.
Active production and sourcing
It is available in Tape & Reel or Cut Tape options.