The circuit is from 1994 National Semiconductor documentation. The component is not easy to obtain, but there are equivalents that can be searched.
This circuit is suitable for incandescent lamps but can be adapted to work with LEDs. The circuit is...
We find this circuit in the 80's own component manual itself. The characteristics of the circuit...
This source, obtained in the 1982 SGS manual, has pre-regulation and provides a current according to...