The LM317 is an adjustable three-terminal positive-voltage regulator capable of supplying more than 1.5 A over
an output-voltage range of 1.25 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.
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. Or, by connecting a fixed resistor between the ADJUST and OUTPUT terminals, the LM317 can
function as a precision current regulator. An optional output capacitor can be added to improve transient
response. The ADJUST terminal can be bypassed to achieve very high ripple-rejection ratios, which are difficult
to achieve with standard three-terminal regulators.