3V rail, 2 µA Iq — the always-on LDO for harsh environments
The TPS79730MDCKREP is a fixed 3V output LDO from Texas Instruments, rated for 10mA continuous output. PSRR is 50dB at 100Hz — enough to knock down the 100/120Hz ripple from a mains-rectified supply before it reaches a sensitive analog load. For a reference rail or a low-noise sensor bias, that ripple rejection matters more than the dropout at light load.
Dropout, protection, and the Power Good flag
Maximum dropout is 0.4V at 10mA — the input rail needs to stay above 3.4V across load and temperature to keep the output in regulation. That is a tight headroom for a 3.3V rail; a 5V rail gives plenty of margin. Built-in over-current and reverse polarity protection mean the part survives a swapped supply or a shorted output without latching up — useful when the board is being debugged or field-swapped without an ESD bench. The Power Good open-drain output asserts when Vout is within regulation, so you can sequence a downstream load or hold a microcontroller in reset until the rail is stable. No external supervisor needed for a basic power-up sequence.
SC-70-5 — tiny but hand-solderable
The SC-70-5 (SOT-353) package is about 2mm x 2mm — small enough for space-constrained designs but still hand-solderable with a fine tip and steady hands. No hot-air station required if you are swapping one on a repair bench. Surface-mount only; the tape-and-reel or cut-tape options cover both production reels and prototype quantities.