Stepable current source 0-20nA

Discussion in 'General Electronics Chat' started by psii, Mar 27, 2013.

  1. psii

    Thread Starter New Member

    Mar 27, 2013

    I could use some input on how to make current source being able to output a current in the tange 0-20 nA. Preferably, I would like to be able to regulate the output current in predefined steps within the specified current range. The current source will be used to emulate a three-lead amperometric glucose cell for testing a controll system I have made.

    I would happily accept all information you guys would be able to provide.
  2. MrChips


    Oct 2, 2009
    All you need is a battery and resistor. For example, a 150MΩ resistor in series with a 3V button cell will give you 20nA.
  3. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    How many steps, and controlled by what?

    What degree of accuracy?

    It there any special consideration to the terminals? Do either need to be grounded? nailed to a power rail? floating?
  4. psii

    Thread Starter New Member

    Mar 27, 2013
    An accuracy of 1 nA would be preferable, but it is not a priority at this point. I mainly need to see that the system works and do not need to concider its performance. The working and counting electrode will be connected to the anode and cathone of a galvanic cell, while the reference will be wrapped around the cell core and provide a potential provide by a configurable potentiostat.

    I guess 3-5 steps would suffice and it could be either voltage or current controlled. Best case, I would use a microcontroller to control it.