Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Current to voltage converter

  1. Oct 9, 2012 #1
    Hi all,

    What is the difference of using an op-amp(transimpedance) vs a precision resistor to convert I-to-V?

    I am trying to linearly amplify a 1nA-10nA AC current with frequency of 10khz and below to a AC voltage and be passed to other circuitry for further processing.

    Thank you for the help, in advance.
     
  2. jcsd
  3. Oct 9, 2012 #2

    sophiecentaur

    User Avatar
    Science Advisor
    Gold Member
    2017 Award

    If you use a precision resistor, the voltage across it may affect the current that you are trying to measure. A transimpedance amplifier will, effectively, be present a low impedance load to your current source and not affect the current. Of course, using a low enough resistor and then measuring a very small voltage would be an alternative. . . . .
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook