Inverting Amplifier maximum output voltage

AI Thread Summary
The discussion centers on the limitations of an inverting amplifier's output voltage, specifically noting that the output voltage does not exceed 8Vrms. This limitation is attributed to the DC power supply voltage of 12V, which restricts the maximum peak voltage. It is highlighted that op amps require a minimum voltage drop from their output to the supply rails, meaning the output cannot reach the full supply voltage. The conversation references the LM741 op amp, indicating that it cannot guarantee output close to the supply rails. Overall, the output voltage swing is constrained by the power supply voltages used in the circuit.
moonkey
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Homework Statement


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


Homework Equations


none


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?
 
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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.
 
Thanks rude man
 
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.
 
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