Device with constant voltage drop in the mA to uA range

John Duffy wrote 09/02/2023 at 05:10 -1 point

Does anyone know of a part that will drop a constant voltage (shooting for about 2 or 3V)  while passing ~3uA through ~5mA.  So like a zener would work except that below a few hundred uA they tend to start to drop towards 0V drop.  Trying to avoid using an opamp for this, but could use a fet or something.  

Doesn't have to be super well controlled, so if it's like 2V at 5uA and 3V at 5mA that's fine, I just need a couple volts drop to have overhead for something.

Update: For this particular application, I ended up replacing this with a source follower mosfet, didn't do quite the same thing (it drops a variable amount and maintains a constant output voltage), but turned out cheaper and to work better in this application.  

Details here:

in the ohms section, referring to Q1.