Dropout and headroom — 0.09 V at 300 mA
The TPS7A1018PDSET is a 300 mA fixed-output LDO from Texas Instruments, delivering 1.8 V with a maximum dropout voltage of 0.09 V at full load. That 90 mV floor means the upstream rail must stay above 1.89 V across load and temperature — a 3.3 V input rail has plenty of headroom, but a 1.9 V rail would drop out under load.
PSRR across frequency — 60 dB at 1 kHz to 35 dB at 1.5 MHz
Power-supply rejection ratio is 60 dB at 1 kHz and rolls off to 35 dB at 1.5 MHz. For a downstream ADC or RF front-end, the 1 kHz band is well filtered, but switching-regulator ripple above 100 kHz passes through with only 35 dB of attenuation — a second-stage LC filter ahead of this LDO may be needed if the upstream switcher runs above 500 kHz. Quiescent current is 2.6 µA typical, rising to 9 µA max including the shutdown and protection bias. This keeps the always-on 1.8 V rail in a battery-powered sensor node below 10 µA overhead — the LDO's own draw is comparable to the MCU's sleep current.
Active lifecycle — no EOL watch needed
It is ROHS3 compliant and suitable for new designs — no last-time-buy planning required. Protection features include over-current, over-temperature, and UVLO, so the part shuts down cleanly on a shorted output or thermal runaway.