Current variable through potentiometer

[Ramana Madishetti]

Hello Everyone,
Wishes for the day.

The project is about to bring up a board.
By using potentiometer i need to vary current range from 1mA to 2mA with the input voltage of 1.5 to 3v and current resolution must be 0.1mA or above will be better.

So, i need to make components selection before that i need to know the block diagram. Suggest me how can i get clarification in this. Is there any IC's for current variable. From where should i start?
Please suggest me. it would be more helpul. And there is a simple block diagram from my side.

Thanks and Regards,
Ramana Madishetty

 

[barry]

I would use a transistor current source. Here's one of about 4,000,000,000,000 pages about it.
http://www.ecircuitcenter.com/Circuits_Audio_Amp/BJT Current_Source/BJT_Current_Source.htm

 

[crutschow]

Getting a constant current source to operate down to a 1.5V input voltage power is difficult but getting one to operate at that output voltage is simple. So is it input voltage or output voltage than needs to go down to 1.5V? Can the circuit operate from a higher power supply voltage?