current to voltage converter

Discussion in 'Homework Help' started by szpati, Aug 13, 2009.

  1. szpati

    Thread Starter New Member

    Aug 12, 2009
    I have very a problem. During the scanning with AFM microscope I measure
    current flowing through the sensor elements that was monitored by a current to voltage converter with adjustable sensitivity (1 µA/V to 1nA/V). I need now to calculate the voltag output into the resistance. I need to write the current to voltage converter. The circuit is linear. i don't know how to calculate this. For example for one measurement the voltage i changing from
    -5.175 V upto -5.126V
  2. StayatHomeElectronics

    AAC Fanatic!

    Sep 25, 2008
    I do not understand what you are trying to calculate.

    You have a current coming from the microscope, I(m). It is sent through a current to voltage (I-V) converter to give you an output voltage, V(m). You have an adjustable resistive element that varies the sensitivity of the I-V converter, R(adj).

    If you have the sensitivity set to 1 uA/V, an output voltage of -5.175V gives you a current of -5.175 uA. Your current change would be 0.051 uA.

    What resistance do you need to calculate the voltage output into? I am not sure what this is referring to.