200 mA LDO with 3 µA quiescent — always-on rail fit
The TPS7A0528PDBZT is a single-output positive LDO from Texas Instruments, delivering a fixed 2.8 V at up to 200 mA continuous output. Its 3 µA quiescent current makes it a natural fit for battery-powered always-on rails — the regulator's own draw sits below the self-discharge rate of a typical lithium coin cell, so a sensor node sleeping for months still wakes with the rail in regulation. The 308 mV maximum dropout at full load defines the headroom needed: the input must stay at least 308 mV above 2.8 V across the load range, or the output falls out of regulation.
Wideband PSRR and protection set
PSRR is specified at 40 dB across a 1 kHz to 1 MHz band — this is unusually wide for a low-Iq LDO. Upstream switching converter noise at 500 kHz or 1 MHz sees the same rejection as lower-frequency ripple, so the LDO cleans the rail without requiring an external LC filter ahead of it. On-chip protection includes over-current limiting, thermal shutdown, and under-voltage lockout (UVLO). The UVLO threshold prevents the output from powering up until the input is high enough to maintain regulation, eliminating brown-out glitches on the 2.8 V rail during system start-up.
SOT-23-3 package and temperature grade
The Enable control pin (active high) lets the system power down the LDO to near-zero current when the load is idle. The 125°C TJ ceiling means the 200 mA output can be sustained at 85°C ambient with adequate PCB copper for heat spreading.