200 mA, 0.3 V dropout — headroom rules the fit
The LDK120PU29R is a fixed 2.9 V output LDO from STMicroelectronics' LDK120 series, rated 200 mA continuous with a maximum dropout of 0.3 V at full load. Plan the input supply margin accordingly.
55 dB PSRR across 120 Hz to 10 kHz
Power supply rejection ratio is 55 dB from 120 Hz through 10 kHz — this covers the fundamental and lower harmonics of mains ripple (100/120 Hz) and the switching frequencies of most DC-DC converters. Quiescent current is 60 µA typical, with a maximum supply current of 100 µA. This low Iq suits battery-powered always-on rails — a sensor node that sleeps with the regulator enabled draws under 100 µA from the battery just for the LDO's own bias.
6-DFN footprint and rework reality
That is a small thermal pad underneath; the exposed paddle is the die attach, not a ground connection. On rework, preheat the board to 150°C, then hit the pad with hot air at 300°C for 8-10 seconds. The package is small enough that the part lifts clean without cooking adjacent passives if you mask them with Kapton.
RoHS and REACH declarations are available from STMicroelectronics on request.