Dropout, quiescent current, and PSRR — the fit decisions
The TPS7A1108PDRVT: Rated for 500 mA continuous output with a maximum dropout voltage of 0.14 V at full load — the input rail must stay at least 140 mV above the 0.8 V output under load to keep regulation. Quiescent current is 2.6 µA typical, which keeps the regulator's own draw negligible in battery-powered designs. PSRR measures 64 dB at 1 kHz, rolling off to 35 dB at 1.5 MHz — the attenuation curve matters when the input rail carries switching noise from a DC-DC converter upstream. Below 100 kHz the rejection is strong enough to clean a buck output; above 1 MHz, additional filtering or layout care is needed.
Package and thermal — board integration note
Housed in a 6-WDFN with exposed pad (supplier package 6-WSON, 2x2 mm). The Enable pin allows the regulator to be shut down for power sequencing or low-power sleep modes.
Protection and operating range
Built-in protection includes over-current, over-temperature, and under-voltage lockout (UVLO). Input voltage range is 3.3 V max, output fixed at 0.8 V — this is a low-VIN, low-VOUT LDO suited for post-regulation from a 1.2 V or 1.8 V rail down to 0.8 V core supplies.