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

A voltage divider in terms of a conductance

  1. Jun 29, 2009 #1
    I am looking at the following application note that goes into nodal analysis of op amps: http://www.maxim-ic.com/appnotes.cfm/an_pk/1939/ and down at the bottom where they're analyzing the Wien bridge oscillator the equation at the negative input of the op-amp taken from the output in terms of conductance is Gf/(Gi+Gf). I'm not sure how they got that - if expressed in terms of resistances that voltage divider is Ri/(Rf+Ri). How does one change the equation for a voltage divider in terms of resistance to terms of conductance?
  2. jcsd
  3. Jun 29, 2009 #2

    The Electrician

    User Avatar
    Gold Member

    In this expression, Ri/(Rf+Ri), substitute:

    1/Gf for Rf
    1/Gi for Ri

    then simplify and you should get the voltage divider formula in terms of conductance.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: A voltage divider in terms of a conductance
  1. Voltage Dividers (Replies: 1)

  2. Voltage divider (Replies: 4)

  3. Voltage divider (Replies: 15)