You are here

Operational Amplifier (Op-Amp) Tester

This calculator will allow you to experiment with operational amplifiers to see how they work. Below is a drawing of how this virtual calculator is set up. This workbench consists of three pieces:

  • The Input Function Generator, also known as the Wave Generator, is a device which provides a voltage wave for use as an input to our op amp circuit. This generator is capable of producing multiple waveforms, which you can select from the input function dropdown. This wave generator is connected directly to the $V_{\text{in}}$ of the operational amplifier. It is also connected to the oscilloscope so that you can see the input voltage to the circuit. On the oscilloscope, this is represented in blue (channel 1).
  • The Operational Amplifier circuit is our circuit design for testing. This setup will allow you to play with operational amplifier configurations for boosting, inverting, or otherwise changing your signal. Making changes to the resistor values and type of operational amplifier will modify the input voltage (from the wave generator). This modified voltage wave, known as $V_{\text{out}}$, can be seen on the oscilloscope in yellow (channel 2). Changing the paramters of the operational amplifier circuit will change this $V_{\text{out}}$ wave, which will be seen on the oscilloscope.
  • The Oscilloscope, is attached to both $V_{\text{in}}$ and $V_{\text{out}}$ of the operational amplifier circuit for the purpose of looking at how the op amp changes voltage. The blue wave (channel 1) on the oscilloscope shows you what is coming into the op amp circuit, and the yellow wave (channel 2) shows you what is coming out of the op amp circuit. This should give you an idea about how to configure an op amp circuit to get the necessary gains/alterations that you need. The oscilloscope has additional settings which can be configured to allow you to better see the voltage waves. Note that if your wave cannot be seen easily on the screen, adjusting the voltage per division to be a larger number should give you a larger viewing area.
Operational Amplifier (Op-Amp)Wave GeneratorOscilloscopeVinVinVinVoutVout
Calculator Settings
Check this box if you wish to hide the help for this calculator for easier use
Input Function Generator
These settings control the voltage input ($V_{\text{in}}$) to the operational amplifier circuit.
The wave function being output by this generator. This is the voltage wave being used for $V_{\text{in}}$.
V
Peak Voltage. This is the "height" of the wave function.
This is the time it takes to complete one "cycle" of the wave.
V
This is a static voltage to be added to the wave. Normally the wave will use 0 volts as its origin. Setting a DC offset will cause the wave to follow the same form but to begin at a different origin point.
Operational Amplifier Circuit
Adjust settings in the op amp circuit.
OpAmp100kΩ100kΩVoutVinR1R2Gain: 2
The type of operational amplifier circuit being used to modify the input $V_{\text{in}}$. An inverting op amp turns a negative input into a positive input (and vice versa). A non-inverting op amp keeps the same sign for an input - positive to positive and negative to negative.
Resistance value of $R_1$.
 
Resistance value of R2
 

The values of $R_1$ and $R_2$ will determine the gain of the op amp (shown in the circuit).

± V
Output voltage saturation cutoff value. Op amps cannot put out more voltage than is provided by the supply ($V_{\text{in}}$). Typically this value is the amplitude of the supply, so a -5V to +5V $V_{\text{in}}$ would be capped at 10V. In practice, an op amp usuallyy has a saturation voltage a bit lower than the expected value. Changing value will allow you to simulate those upper bounds.
Oscilloscope
The fidelity of the scope increases the accuracy, but slows down the render time. If you are seeing inconsistencies in your graph, you should increase the fidelity. This may be necessary in situations that involve very rapid changes in voltage.
Cursors
V
This value allows you to move the oscilloscope cursor to a specific value to check measurements by aligning the cursor on the graph with the waveforms. This cursor is pink on the scope.
V
This value allows you to move the oscilloscope cursor to a specific value to check measurements by aligning the cursor on the graph with the waveforms. This cursor is green on the scope.
Checking this box will have the effect of linking the two cursors. Increasing or descreasing one will do the same with the other. Useful for measuring comparing differences between voltage values.
Channel 1 (Input)
Settings for the Channel 1 voltage, which is attached to the $V_{\text{in}}$ wave from the waveform generator. This waveform is blue on the scope.
V
This field allows you to change the voltage per division for ONLY channel 2, allowing for a wider range of view. Note that a "division" is the space between two horizontal black lines on the scope. Vertical divisions remain unchanged.
V
This allows you to offset the waveform on the scope by a certain voltage. This allows you to move the waveforms if necessary to make for easier viewing
Channel 2 (Output)
Settings for the Channel 2 voltage, which is attached to the $V_{\text{out}}$ wave from the op amp circuit. This waveform is yellow on the scope.
V
This field allows you to change the voltage per division for ONLY channel 1, allowing for a wider range of view. Note that a "division" is the space between two horizontal black lines on the scope. Vertical divisions remain unchanged.
V
This allows you to offset the waveform on the scope by a certain voltage. This allows you to move the waveforms if necessary to make for easier viewing
Note that the information presented in this article is for reference purposes only. Antique Electronic Supply makes no claims, promises, or guarantees about the accuracy, completeness, or adequacy of the contents of this article, and expressly disclaims liability for errors or omissions on the part of the author. No warranty of any kind, implied, expressed, or statutory, including but not limited to the warranties of non-infringement of third party rights, title, merchantability, or fitness for a particular purpose, is given with respect to the contents of this article or its links to other resources.