The humble LM317 adjustable voltage regulator is everywhere. From wifi routers, to high spec lab equipment. Given a noisy input and a variable load, a voltage regulator will give a nice clean, ...

Take advantage of current control topologies without self-heating error while retaining the 317/337's fault protection ...

The circuit “reverses” the standard hookup of the LM317 adjustable regulator. Normally, the ADJ pin connects to a voltage divider on V OUT, and the LM317 regulates V OUT by keeping it 1.25V above V ...

The LM317 was trying to force 40 mA into a white light-emitting diode (LED), so that 1.25 V across RS, the 30.1-ohms sense resistor, would cause a 41-mA current to flow—if you had enough voltage.

Reading through the app note, the transient response to changes in voltage is less than 10 usec and the deviation is small. That seems pretty good for something like a laser diode. More options ...