1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Inverting Amplifier maximum output voltage

  1. Nov 9, 2012 #1
    1. The problem statement, all variables and given/known data
    I'm doing a physics lab that involves an inverting amplifier. I'm pretty crap when it comes to electronics. I've discovered that the output voltage won't go past 8Vrms.

    The amplifier is like the one here
    http://en.wikipedia.org/w/index.php?title=File:Op-Amp_Inverting_Amplifier.svg&page=1


    2. Relevant equations
    none


    3. The attempt at a solution
    I'm thinking that this is due to the DC power supply for the op amp being 12V. Would I be right in thinking that the maximum Vp (peak voltage as measured on the oxcilloscope) which in my case is 11.5V is due to the 12V DC power supply?
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Nov 9, 2012 #2

    rude man

    User Avatar
    Homework Helper
    Gold Member

    You are obviously using dual +/- 12V supplies for your op amp.

    8V rms is about 22.4V peak-to-peak which is close to 24V, the sum of your supplies.

    Decidedly, you are being limited by the power supply voltages! Every op amp requires a minimum voltage drop from its output to either supply.
     
  4. Nov 10, 2012 #3
    Thanks rude man
     
  5. Nov 11, 2012 #4

    CWatters

    User Avatar
    Science Advisor
    Homework Helper

    See "Output Voltage Swing" on page 3.

    http://www.ti.com/lit/ds/symlink/lm741.pdf

    For this opamp they don't guarantee you can get within 3 or 4 V of the supply rails. eg on +/-15V rails the output can swing to +/- 12V at best depending on the output load.

    Just one of the many ways a real world opamp differes from an ideal amp.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Inverting Amplifier maximum output voltage
Loading...