300 mA in a SOT-323-5 — what it buys the layout
The STMicroelectronics LDK130C29R is a single-output positive LDO regulator delivering a fixed 2.9 V at up to 300 mA from a maximum 5.5 V input rail. It comes in a 5-pin SOT-323-5 package — the same footprint as SC-70-5 and SOT-353 — which keeps the board area tight for space-constrained power domains. The 0.4 V maximum dropout at full load means you need at least 3.3 V on the input to hold the 2.9 V output steady through line transients. The enable pin lets the system power-cycle the rail without a separate load switch.
PSRR and noise — where the 55 dB matters
The LDK130C29R holds 55 dB of power-supply rejection from 120 Hz through 10 kHz. That covers the fundamental and lower harmonics of switched-mode supplies and 50/60 Hz mains ripple. For an analog sensor bias rail or a low-power RF front-end, this PSRR band helps keep supply noise out of the signal path without adding a post-filter LC stage.
Temperature range and protection — industrial and automotive use
On-chip protection includes over-current and over-temperature shutdown — no external watchdog needed for the basic fault cases.