20mA surface mount LED constant current IC

These are not really resistors, but are in fact a linear constant current driver. They have a maximum input voltage of 45 volts and have a fixed output current of 20mA.

They come in a tiny SOD-123 surface mount package.

Use them just like a resistor. The only requirements are that you don't exceed their power dissipation rating and that you connect them the right way around!

Made by OnSemi, part number NSI45020T1G. Datasheet is here.