Square Wave Generator Circuit with Op-Amp IC 741

The Op-amp 741 IC is a popular and versatile operating amplifier that can be utilized in a variety of applications such as comparator, wave generator amplifier, and so on.

An electronic circuit that generates a square wave is known as a square wave generator. The square waveform generator based on operational amplifiers is a simple circuit commonly used in function generators. The 741 op-amps is used in the square wave generator circuit.

Square Wave Generator Op Amp

We will learn about the Square Wave Generator Circuit using the Op-Amp IC 741 in this tutorial. The Triangular Wave Form can be generated with the operational amplifier.

Hardware Required

  • Op-Amp IC-LM741
  • Resistor-10KΩ
  • Resistor-12KΩ
  • Capacitor-1 µF, 16V (Electrolytic Capacitor)

What is an Operational Amplifier OP-AMP?

An operational amplifier (OA or op-amp) is a high-gain amplifier that is directly linked and fed with both positive and negative sources, allowing it to obtain excursions both above and below the ground or reference point. It is distinguished by its sensitivity to externally introduced input in terms of frequency, phase change, and high gain. It has a high input impedance (Z) and a very low output impedance due to its design. The symbol is as follows:

Op-Amp IC LM741

The LM741 is a multi-featured operational amplifier IC. The integrated circuit is available in a variety of packaging. The IC’s internal circuitry contains a total of 20 transistors. The IC is suitable for a variety of analog tasks.


It is suited for use in battery-operated circuits because of its high gain, low current consumption, and wide supply voltage. Furthermore, the IC is overload protected on both ends, i.e. input and output, which protects the IC’s internal circuitry from damage caused by overload.

LM741 OP-AMP Pin diagram:

Square Wave Generator Circuit Diagram

The square wave generating circuit employing Op-Amp is depicted in the diagram below. One capacitor is linked to the inverting terminal of an op-amp with one pin connected to the ground, and a resistor is also connected to the inverting terminal to output for charging and discharging the capacitor.

Square Wave Generator Circuit

Two resistors are used to make one voltage divider, which is connected to the output and ground at the non-inverting pin.

Working of Square Wave Generator Using Op-Amp 741

Assume that the voltage at the inverting terminal is V2, which is the same as the voltage across the capacitor. Let’s further assume that the voltage at the non-inverting terminal is V1. Differential input voltage is defined as the voltage difference between the non-inverting and inverting terminals, and it is given as Vin.

At the initial state when the capacitor is fully discharged, the voltage at inverting pin will be zero, i.e. V2 = 0V

Therefore, input differential voltage (Vin) = V1-V2 = V1-0 = V1

When Vin is positive, the output is positive, and the capacitor begins to charge through resistor R2 towards a positive saturation voltage until V1 = V2.

When the capacitor voltage rises slightly higher than the differential voltage V1.

Negative Vin = V1-V2 (V2>V1)

After then, the output will be changed from positive to negative saturation voltage. Because V2 is greater than Vout in this case, the capacitor begins to discharge through resistor R2. The output will transition to positive saturation voltage once more after reaching V2, which is somewhat less than V1. This process is repeated many times, resulting in a square wave.

Circuit Simulation

Proteus Software can be used to model the circuit. The Oscilloscope output is excellent when the circuit below is replicated. Change the value of the resistors to see how the waveform changes.


I hope you understand how to design a square Wave Generator Circuit with OP-AMP IC 741. We MATHA ELECTRONICS will be back soon with more informative blogs soon.

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