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

Gain-Bandwidth product question

  1. Aug 21, 2009 #1
    If I have an op-amp with say, a hypothetical bandwidth of 1 MHz, and I use it in a configuration where I have a gain of 10, I know that I will only have unity gain at an input frequency of 100kHz. What I am wondering is how I go about calculating what the effective cutoff frequency is, i.e. where the gain is down -3dB? Thanks!
  2. jcsd
  3. Aug 21, 2009 #2


    User Avatar
    Science Advisor

    No that's incorrect. So long as the other poles (apart from the dominant pole that sets the 1MHz GBWP) are above 100kHz then 100Khz will indeed be a very good approximation to the actual -3dB frequency.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Gain-Bandwidth product question
  1. Gain bandwidth product (Replies: 3)