It requires only two external resistors to set the output voltage. The LM317 features a typical line regulation of 0.01% and typical load regulation of 0.1%. It also includes current limiting, thermal ...

(This is a GOOD standard application shown in every LM317 data sheet.) Because the output pin is 1.25 V above the adjust pin, the current I = 1.25 V/RS will flow—if there's enough voltage.

The LM317 forces 1.25V across the 62Ω resistor, causing 20 mA to flow from the output pin through the resistor, and to the black terminal of the current source. The circuit maintains this regulation ...

Given a noisy input and a variable load, a voltage regulator will give a nice clean, stable output voltage ... describes how the LM317 can be used to regulate current rather than voltage to ...

See this diagram,I've been told the the proprietary drivers offer some extra protection from very short spikes (on power up and shutdown) in the current ... ve built several LM317 based drivers ...