The Texas Instruments LM317LIBPX is an adjustable positive voltage regulator in a 6-VFBGA package, delivering up to 100 mA output current from a 1.2 V to 37 V output range. The 6-VFBGA (6-DSBGA) footprint is the key differentiator — this is the LM317 shrunk into a tiny BGA for space-constrained boards where a standard TO-220 or SOT-223 won't fit.
PSRR 80 dB~65 dB at 120 Hz — the noise-sensitive rail angle
The PSRR is specified at 80 dB to 65 dB at 120 Hz, which means this regulator attenuates 120 Hz ripple from a rectified mains input by a factor of roughly 10,000 to 1,800. For an analog supply rail feeding an op-amp or ADC front-end, that ripple rejection budget is the difference between a clean 1.2 V reference and a 60 Hz hum component riding on the output.