LP2957/LP2957A 5V low-dropout regulator for µP applications
The LP2957/LP2957A provides a regulated 5 V output with very low dropout (470 mV typical at 250 mA) and ultra‑low quiescent current (150 µA typical at 1 mA load). It includes electronic shutdown, an error‑flag output, reverse‑battery protection, and tight line/load regulation (0.04 % typical). The device is offered in 5‑lead TO‑220 and TO‑263 surface‑mount packages.
Typical application circuits show snap‑on/snap‑off output control, external capacitor requirements, and heatsink calculations. The datasheet also lists absolute maximum ratings, electrical characteristics, thermal regulation formulas, and physical dimensions for board layout.
| Output Voltage | 5.0 V (typical) |
|---|---|
| Dropout Voltage at 250 mA | 470 mV (typical) |
| Maximum Output Current | 250 mA (guaranteed) |
| Temperature Coefficient | 20 ppm/°C (typical) |
| Line Regulation | 0.04 % (typical) |
The typical dropout voltage is 470 mV when the load current is 250 mA.
The regulator is offered in a 5‑lead TO‑220 package and a 5‑lead TO‑263 surface‑mount package.
A logic‑low signal (below about 1.2 V) on the shutdown pin turns off the regulator output.