The LM317 is an adjustable three-terminal positive-voltage regulator capable of supplying more than 1.5 A over an output-voltage range of 1.2 V to 37 V. It is exceptionally easy to use and requires only two external resistors to set the output voltage. Furthermore, both line and load regulation are better than standard fixed regulators. The LM317 is packaged in the KC (TO-220AB) and KTE packages, which are easy to handle and use. In addition to having higher performance than fixed regulators, this device includes on-chip current limiting, thermal overload protection, and safe-operating-area protection. All overload protection remains fully functional, even if the ADJUST terminal is disconnected. The LM317 is versatile in its applications, including uses in programmable output regulation and local on-card regulation.
The LM317 is a three‑terminal positive‑voltage regulator that can supply more than 1.5 A over an output‑voltage range of 1.2 V to 37 V. It requires only two external resistors to set the output voltage and includes on‑chip current limiting, thermal overload protection, and safe‑operating‑area protection.
The datasheet provides absolute‑maximum ratings, recommended operating conditions, electrical characteristics, and numerous application circuits such as adjustable voltage regulators, precision current limiters, and battery‑charger designs. An important notice about warranty and product availability is included at the end.
| Maximum output current | ≥ 1.5 A |
|---|---|
| Input‑to‑output differential voltage | 3 V to 40 V |
| Reference voltage (Vref) | 1.25 V |
| Thermal resistance (KC package) | 0.00008 °C/W |
It can supply more than 1.5 A of output current.
The internal reference voltage is 1.25 V.