What the 2.85V rail buys you
The TLV733285PDQNR is a fixed 2.85V output LDO from TI's TLV733 family, delivering 300mA continuous with a dropout of 0.29V max at full load. That tight dropout means it keeps the output regulated even when the input rail dips close to 3.14V — useful for battery-powered gear where the cell voltage sags under load. The enable pin lets a microcontroller shut the rail entirely when the load is idle.
PSRR and noise rejection across the band
PSRR is 68 dB at 100 Hz, tapering to 28 dB at 100 kHz. That 68 dB at line frequency means the regulator knocks down 120 Hz ripple from a rectified mains supply by a factor of ~2500 — clean enough for an analog front-end sampling at low rates. The roll-off above 10 kHz means upstream switching noise at a few hundred kHz will pass through unless filtered ahead of the LDO. For a 2.85V rail feeding a 3.3V-tolerant ADC reference or a small-signal amplifier, the PSRR profile sets the usable bandwidth. If the load draws fast current transients, the output capacitor's ESR and the regulator's loop response matter more than the DC PSRR number.
Package and board-fit: 4-X2SON
The 4-X2SON package measures 1.0 mm × 1.0 mm with a 0.65 mm pitch — small enough to tuck into a corner of a multi-layer board. Mounting is surface-mount only — no through-hole variant exists.
Protection and temperature range
Built-in protection covers over-current, over-temperature, short-circuit, and under-voltage lockout (UVLO). The UVLO threshold prevents the output from turning on until the input rail is high enough to keep the pass element in regulation — avoids brown-out glitches on power-up.