# How to convert sine wave into square wave using op-amp

1. ## Urgent!!!

hi..can anybody tell me how to convert a sine wave form into a square waveform by using op-amps(IC-741 specifically)....its my term project and i have just half a week left to submit it so plzzz hurry and reply..plz be elaborative and include diagrams if possible..thanks.regards

2. ## Re: Urgent!!!

Dude, no one in this forum will do someone else's work. We only HELP. It is your work so you have to do it yourself.

In order to convert a sine wave into a square wave you only have no use an Opamp (like IC-741) using a non-inverting amplifier circuit with a very large gain.

The very large gain willl make the circuit saturate quickly, transforming your sine into a square.

This site has exactly what you need:
http://www.wisc-online.com/Objects/V...spx?ID=SSE7906

You should use the "non-inverting amplifier", and not the "inverting" for 2 reasons:

1) It does not invert the sinal (I supose that's what you want)

2) It has very high input impedance (which is always good)

3. ## Re: Urgent!!!

hmmm..yeah that'l do it..thanks..ur a life saver!..:D

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4. ## Urgent!!!

Or just use the opamp like a comparator - no feedback.

Keith

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5. ## Re: How to convert sine wave into square wave using op-amp

Or just use the opamp like a comparator - no feedback.
Yeah, that's right. Don't know how I didn't remebered that, how silly of me

6. ## Re: How to convert sine wave into square wave using op-amp

ohk thank you for your feedback . i was actually able to "test run" my circuit in the lab..but you see there's now a tiny miny BIG problem..i am now suppose to convert my square wave output into a trangular wave.:(..Now how i do that?..and also to convert a sine wave into square wave using IC-741 op-amp?...and my project is now worth 50% weightage of my total course..what a misery!!

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7. ## How to convert sine wave into square wave using op-amp

You need an integrator.

Keith

8. ## Re: How to convert sine wave into square wave using op-amp

Keith is right, you need an integrator. Check this out:

http://www.wisc-online.com/objects/V...spx?ID=SSE5303

9. ## Re: How to convert sine wave into square wave using op-amp

that was an excellent help sir!!...i really appreciate it..and the slide show well that was so elaborative and easy to understand:)..thanks once again.you ppl are great help..kkep up the good work:D

10. ## Re: How to convert sine wave into square wave using op-amp

hey!! hey.!!:D..i made the project and m just a day away from showing it to my teacher..guys ive made the integrator and adjusted the but i didnt have any idea what i was doing actualy..i read it somewhere that if you change the resistance and capacitance you can adjust the wave into traingular wave but what i want to ask is that is there any specific easy to understand "formula" for voltage output of an integrator?..not that one that includes an 'integral' type of stuff but a simple universal formula so i can easily understand it and make my teacher understand it as well:)..thanks waiting for ur feedback

11. ## How to convert sine wave into square wave using op-amp

Unfortunately an integrator integrates, so it is difficult to avoid integration in the explanation:

http://en.wikipedia.org/wiki/Operati...ing_integrator

In simple terms, the output will decrease (because it is inverting) at a rate determined by the resistor and capacitor at dV/dT=-Vin/RC so if you had 100k and 100nF and a 5V signal, for example, the output would change at the rate of 500V/s.

Keith.

The simple explanation, by the way, is that the opamp keeps the inverting input at zero volts, so the current in the resistor is Vin/R. This current must go through the capacitor and the equation for a capacitor charge (Q=CV), when differentiated gives I=C.dV/dt. So, dV/dt=I/C = Vin/RC. The minus sign appears because of the dire4ction of the current in the capacitor, resulting in -Vin/RC.

Keith.

12. ## Re: How to convert sine wave into square wave using op-amp

Perhaps TANSAH wants to see an integral explicitely in the formula.
Therefore, read this explanation for an intergator circuit (without signal inversion):
* Voltage across a capacitor: Vc=(1/C)∫idt with i=Vin/R (due to virtual ground at the inverting opamp terminal)
* Thus, Vc=(1/RC)∫(Vin)dt.
* For Vin=const. this leads to Vc=(1/RC)*Vin*t (>>linear ramp prop. to time t).

Perhaps this helps.

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13. ## Re: How to convert sine wave into square wave using op-amp

yeah i think i have understood most of it..thanks once again ppl:)

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