The LM317 is an adjustable 3–terminal positive voltage regulator capable of supplying in excess of 1.5 A over an output voltage range of 1.2 V to 37 V. This voltage regulator is exceptionally easy to use and requires only two external resistors to set the output voltage. Further, it employs internal current limiting, thermal shutdown and safe area compensation, making it essentially blow–out proof. The LM317 serves a wide variety of applications including local, on card regulation. This device can also be used to make a programmable output regulator, or by connecting a fixed resistor between the adjustment and output, the LM317 can be used as a precision current regulator.
The LM317 is a three‑terminal adjustable positive voltage regulator capable of delivering over 1.5 A with an output range of 1.2 V to 37 V. It includes internal current limiting, thermal shutdown, and safe‑area compensation, making it robust for a wide variety of applications such as on‑card regulation and programmable output sources.
The datasheet provides maximum ratings, electrical characteristics, typical application circuits, package options (D2PAK and standard 3‑lead), and recommended external components for stability and ripple rejection. Ordering information and regulatory notes are also included.
| Maximum Output Current | 1.5 A |
|---|---|
| Output Voltage Range | 1.2 V to 37 V |
| Available Packages | Surface Mount D2PAK, Standard 3‑Lead Transistor Package |
| Operating Temperature Range | -40 °C to +125 °C |
| Input‑Output Voltage Differential | 40 V |
| Thermal Resistance (Junction‑to‑Ambient) | 65 °C/W (case 221A) |
| Reference Voltage | 1.25 V |
The LM317 can supply up to 1.5 A of output current.
The output voltage is adjustable from 1.2 V to 37 V.
It is available in a surface‑mount D2PAK package and a standard 3‑lead transistor package.
The regulator maintains a typical reference voltage of 1.25 V.