# What is Inverting op amp: Definition and 15 Discussions

This article illustrates some typical operational amplifier applications. A non-ideal operational amplifier's equivalent circuit has a finite input impedance, a non-zero output impedance, and a finite gain. A real op-amp has a number of non-ideal features as shown in the diagram, but here a simplified schematic notation is used, many details such as device selection and power supply connections are not shown. Operational amplifiers are optimised for use with negative feedback, and this article discusses only negative-feedback applications. When positive feedback is required, a comparator is usually more appropriate. See Comparator applications for further information.

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1. ### Inverting op amp frequency response Bode plot help

Using analog discovery 2 kit and the bode plot produced by the network analyzer is off. The scope looks fine and everything is behaving how it should except for the bode plot. The magnitude of the bode plot will start at the correct dB then right before tapering off it shoots up a few dB and...
2. ### Engineering Practical design of an inverting Schmitt trigger with noise tolerance

This is regarding the positive feedback of an Op-Amp and the inverting Schmitt trigger. This is a typical inverting Schmitt trigger - I need to design the Schmitt trigger such that I have a threshold voltage of around 2V, when my ##+-V_{CC} = 8V##. The slew rate of the Op-Amp allows for a...
3. ### I Checking for negative feedback in a circuit

This is the circuit in question. During lecture, when checking whether this was negative feedback, my instructor said that if the v_out increases, then v- increases as well, which would lead to the next v_out decreasing because v_out = A(v+ - v-). I get how if v- increases the next v_out would...
4. ### Inverting a signal up to 100mV using op amps

Greetings, I'd like to invert a signal I get from a photodetector (the signals are up to 100 mV). I decided to use an inverting op amp circuit for that, however, when looking online through the op amp catalogs - the minimum input voltage in the descriptions is a few volts while my input would...
5. ### Need some insight into an inverting op amp example

Currently working through a chapter on op amp circuits, fundamentals. Came upon this practice problem in the section on inverting op amps imgur link: http://i.imgur.com/2DrQLXk.png imgur link: http://i.imgur.com/7KRKzKC.png A working of this problem is not given. I got the correct answer...
6. ### Output Impedance of an Inverting Op Amp

Homework Statement Hello, I just came across a design problem based on an inverting op amp. The requirement output values are -25G and not greater than 1kOhm output impedance. With inputs 1V p-t-p and 75Ohms input impedance Choosing values for the gain seem fairly easy, but how these values...
7. ### Engineering Inverting Op Amp Circuit: Calculating Output Voltage with Feedback Loop

Homework Statement Write output voltage in terms of input voltages for the circuit drawn. I drew the circuit and then feed back loop. Homework Equations Ohms Law V=IR Basic Properties of Op Amps (ideal), voltages are assumed equal at both inputs... The Attempt at a Solution The...
8. ### Inverting OP AMP with 'hanging' resistor in feedback network

Homework Statement Find Vo/Vin.I understand perfectly how to do this question. It simply involves an application of ohm's law to find i1, then KVL around the first loop. KCL at the top, and KVL around the second loop. Then to solve simultaneously. My issue however Is why the mechanics of...
9. ### Calculating Hybrid Parameters for an Inverting Op Amp

Hi guys :smile: This question has been bugging me for a REALLY long time so thanks in advance for the help :biggrin:! Homework Statement Calculate the Hybrid Parameters for an inverting op amp shown below: https://www.dropbox.com/s/45mjldud2ar5pwg/invOpAmp.jpg And I need to get it...
10. ### Inverting Op Amp Homework - Solve V(output) Equation

Homework Statement http://www.freeimagehosting.net/jqqoz Homework Equations V(output) = V(input)(R2/R1) The Attempt at a Solution The equation above is valid if the back part of the upper circuit (involving R3,R4 and the Earth wire) does not exist. I tried to improvise with it by...
11. ### Speaker/Microphone and Inverting Op Amp

1) What is a typical voltage level coming from an 8Ω speaker being used as a microphone to record a human voice at average volume? I kept forgetting to bring it to school to measure it's output with the oscilloscope, so I'm wondering if anyone here knows it. 2) I seem to remember reading...
12. ### Inverting OP amp cutoff frequency

Homework Statement 1. Using the LM324 op amp build an inverting amplifier with a gain of 50. Measure the cut-off frequency 2. Plot your results on a graph as a function of log(frequency). Comment on the results I have done this in a lab and then graphed it, it seems to be around...
13. ### Inverting OP AMP analysis solution problem

Hello Physics Forums community, I'm a new member and this is my first post. I have a circuits exam tomorrow, and though I grasp the majority of the material I'm having a hard time understanding the solution to a HW problem that I attached as a picture. Problem: Show that the circuit has...
14. ### Inverting op amp with positive input NOT grounded

For an inverting op amp with the positive input grounded, the equation for V(out) is (Vin)*Rf/Rin. Thats fine But what if the positive input is not grounded? What if there is a voltage applied to that input as well? How would I find V(out) when the positive input voltage is larger than the...
15. ### Understanding the Behavior of Inverting Op Amp Circuit with Switched Terminals

please look at this circuit http://hyperphysics.phy-astr.gsu.edu/Hbase/Electronic/ietron/inva2.gif The transfer function for the the circuit above is Vout = (-Rf/Rs)*Vs if I were to switch the terminal of the op amp so that Vin is inputted into Vp and Vn =0 instead (everything is the same...