Noise-sensitive rail regulator — PSRR and dropout
The LP5900SD-2.2/NOPB is a fixed 2.2V output LDO from Texas Instruments, rated for 150 mA continuous output. Its PSRR starts at 85 dB at 100 Hz and rolls to 40 dB at 100 kHz — that 85 dB floor at line frequency is what keeps 50/60 Hz hum off an analog supply rail. Maximum dropout is 150 mV at the full 150 mA load, so the input rail needs only 2.35 V to hold regulation. Quiescent current is 50 µA typical, making it a candidate for battery-powered always-on blocks where every microamp counts.
Package, footprint, and thermal pad
Supplied in a 6-WDFN exposed-pad package (6-WSON, 2.2 mm x 2.5 mm body). The exposed pad is the main thermal path — the PCB layout must solder it to a copper plane for the 150 mA continuous rating to hold without hitting the over-temperature shutdown. Mounting is surface-mount only. The Enable pin (Control Features) lets the system shut the regulator down; the quiescent current drops to near zero when disabled.
Active production — no LTB pressure
Product status is Active with ROHS3 compliance. Available in Tape & Reel (TR) or Cut Tape (CT) for prototyping.