# How to convert square wave 2 sine wave.

Discussion in 'General Electronics Chat' started by amruth11, Nov 3, 2011.

1. ### amruth11 Thread Starter Member

May 24, 2011
49
0
Hi, i would like to convert a square wave that i made using a 555 into a sine wave. It can include ICs, diodes, resistors, transistors and capacitors but i dont want to use a filter or something else and i would like it to be low cost. If it is not easy i would like a circuit which will make a sine wave directly. It can contain the items mentioned above and has to be low cost. The frequency range is between 50Hz to 600KHz max. Thx in advance and eagerly waiting for replies.

2. ### iONic AAC Fanatic!

Nov 16, 2007
1,420
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It really depends on how perfect a sine wave you want and what you are using it for...
What is the square wave peak voltage?

Check out this link, it may help some:
Square wave to sine wave conversion

Last edited: Nov 3, 2011
3. ### Adjuster Well-Known Member

Dec 26, 2010
2,147
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This may require a lot of work, particularly given the wide frequency range. Would it not be simpler to make a sine wave oscillator in the first place?

4. ### amruth11 Thread Starter Member

May 24, 2011
49
0
Sorry for the late reply guys. I dont know what is the peak voltage and my square wave goes from positive, zero and back to positive so i dont know how to find the peak to peak voltage. I can also make a sine wave generator fro the first but i dont no any circuits about it, if any one of u could give me a circuit it would be appreciated. It dosent have to be really perfect of a sine wave but somewhat close to perfect.

5. ### davebee Well-Known Member

Oct 22, 2008
539
46
The best way I can think of would be to pass the square wave into a walking-ring counter and then combine the outputs with resistors.

The results will have a stairstep appearance, but can become very close to a pure sine wave mathematically.

The incoming square wave will have to be a multiple of the output sine - 6, 8, 10, or more, depending on the counter circuit that you use.

The beauty of this circuit is that it can make a fairly clean sine over a very wide range of frequencies.

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6. ### ErnieM AAC Fanatic!

Apr 24, 2011
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How about square, triangle, a sine wave out of one chip? While both the XR-2206 and ICL8038 have gone obsolete both are still well represented on Ebay. I suspect these may not be made be the original manufacturers but at the price they are worth a look-see.

You can find data sheets and schematics all over the web for these.

XR2206: 2.50/free shipping
ICL8030: 2.20/free shipping

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7. ### amruth11 Thread Starter Member

May 24, 2011
49
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Yes thanks but i need a circuit for this, plz tell me if u find any.

8. ### thatoneguy AAC Fanatic!

Feb 19, 2009
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The Datasheet usually has an example circuit showing off the functions, including this one for the first one mentioned above (XR2206).

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9. ### someonesdad Senior Member

Jul 7, 2009
1,585
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If you don't need something precise, you could stick in two integrators (see this thread).

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10. ### amruth11 Thread Starter Member

May 24, 2011
49
0
Hi guys, i saw this circuit on the net which seemed easy,simple and effective which is in my freq. range but the prob. is that there are no values mentioned. If u guys could find out the values and tell me it would be helpful. This is the link for the circuit "http://www.electronics-diy.com/function-generator-kit-xr2206.php"

11. ### thatoneguy AAC Fanatic!

Feb 19, 2009
6,357
718
They don't put the values in the schematic so that you buy the kit from them. That lets them make a little more money to make new kits, and you get a guaranteed working function generator, provided you solder it together correctly.