300 mA LDO with 680 nA quiescent — the battery-life spec
The Toshiba TCR3UG25A,LF is a fixed-output 2.5 V LDO regulator rated for 300 mA continuous output. Its standout number for battery-powered or always-on loads is the 680 nA quiescent current — that is the current the regulator itself draws just to stay alive, and at sub-microamp levels it barely registers against the self-discharge of a lithium cell.
Dropout and protection — what the 0.327 V max means
Maximum dropout voltage is 0.327 V at 300 mA load. Protection features include inrush current limiting, over-current, and thermal shutdown — the regulator handles start-up into a discharged capacitor without the output overshooting, and folds back or shuts down if the load exceeds the rating or the die temperature crosses the threshold. The enable pin lets the system power down the regulator completely — when pulled low, the output goes to high-impedance and the quiescent current drops to near zero, which is useful for sequencing rails or saving power in a sleep state.
Package and temperature — board-fit notes
Housed in a 4-XFBGA, WLCSP package (4-WCSP-F, 0.65 x 0.65 mm footprint). This is a wafer-level chip-scale package — no plastic overmold, the die backside is the top of the package. The small footprint saves board area but the solder balls are under the die, so the PCB land pattern must match the Toshiba recommended layout exactly; a 0.35 mm ball pitch demands careful solder-paste stencil design. The package itself is surface-mount and RoHS3 compliant per the lifecycle record.
The part is a single-source LDO — no pin-compatible second-source is listed. The closest functional sibling in the same TCR3UG series is the TCR3UG25B,LF, which shares the same output voltage, current rating, quiescent current, and package; the difference is in the output voltage tolerance or ordering code suffix, not the parametric fit.