I need design a variable precision current source which able to produce 1nA to 10mA. The current output will be controlled through a Micro controller using a DAC. The purpose this circuit is to calibrate another device which need 1nA to 10mA.
I did some research and found below options:
Analog Devices: Precision Nanoamp Bidirectional Current Source Not enough information to how can be modified for my application
simple opamp and Mosfet which output current should be I = Vdac/(R4 or R3) Figure
Also I read about Multi-Range Current Pump too.
simulate this circuit – Schematic created using CircuitLab
(*forget about the part numbers on drawing, just for reference)
Please let me know if any of these option will work for me, or if there is better option out there.
How can I design a precision 1nA - 10mA current source circuit?