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National Semiconductor LP2957/LP2957A 5V Low-Dropout Regulator Datasheet
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.
National Semiconductor LP2957 specifications
| 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) |
Source: National Semiconductor LP2957/LP2957A 5V Low-Dropout Regulator Datasheet
All National Semiconductor LP2957 documents by type
Ratings, dimensions and ordering codes, for selection and design work.
Questions answered in these manuals
What is the typical dropout voltage of the LP2957 at 250 mA?
The typical dropout voltage is 470 mV when the load current is 250 mA.
From: National Semiconductor LP2957/LP2957A 5V Low-Dropout Regulator Datasheet
Which package types are available for the LP2957?
The regulator is offered in a 5‑lead TO‑220 package and a 5‑lead TO‑263 surface‑mount package.
From: National Semiconductor LP2957/LP2957A 5V Low-Dropout Regulator Datasheet
Which package types are offered for the LP2957?
It is available in five‑lead TO‑220 and TO‑263 (plastic surface‑mount) packages.
From: National Semiconductor LP2957/LP2957A 5V Low-Dropout Regulator Handbook
How is the shutdown function activated?
A logic “LOW” below 1.2 V applied to the shutdown input disables the regulator; a pull‑up resistor may be required.
From: National Semiconductor LP2957/LP2957A 5V Low-Dropout Regulator Handbook