Is it possible to generate a sinewave from a triangular wave? I need some sort of sinewave generator and all of the chips I have found which generate a sine wave are no longer being sold. Any help would be great!

 

Hi,

You're probably unable to find the old ICL8038. Go to Mouser Electronics and get an NTE864 (I think the part # is 522-NTE864). It's the same circuit.

 

Originally posted by beenthere@Apr 18 2006, 12:46 AM
Hi,

You're probably unable to find the old ICL8038. Go to Mouser Electronics and get an NTE864 (I think the part # is 522-NTE864). It's the same circuit.

[post=16275]Quoted post[/post]​

I did see the ICL8038 and another one similar made by maxim, but I couldn't find anywhere that sold the chip. The NTE864 is exactly what I need! Thanks!

 

I need to generate a 500 Hz sine wave. It would be nice if I could adjust it from 1 to 1000 Hz. I bought an NTE864 yesterday. I've been playing with all the resistor and capacitor values I can think of and I still can't get anything but a 60 hz triangle wave. Can somebody please help me out here? Thanks.

 

Find a datasheet for an ICL8038. There are many sample applications in it.

See if you can find Intersil's application note AN013
You'll find it quite helpful. Or just click below.

Datasheet:
http://www.intersil.com/cgi-bin2/Ms...sFind.cfg&host_id=2&page_id=33142&query=AN013

Application Note 13:
http://www.intersil.com/cgi-bin2/Ms...sFind.cfg&host_id=2&page_id=32759&query=AN013

 

maybe a wienbridge op amp circuit could do the trick?

 

Of course, and the sine wave would be a lot higher quality than the 8038's. The National Semiconductor op amp collection has one in it.

 

An op amp integrator will turn a triangle wave into a very close appoximation of a sine wave. It will not be pure, but you would have trouble telling the difference with the naked eye. Here is a variation I've shown several times in other posts.

In this thread SgtWookie was kind enough to do a SPICE simulation, I'll show the thread and the specific post. The thing I like about Sarges simulation is it shows the sine wave.

http://forum.allaboutcircuits.com/showthread.php?t=10755

http://forum.allaboutcircuits.com/showpost.php?p=64466&postcount=13

 

maybe a wienbridge op amp circuit could do the trick?

Yep, that would do it.

However, if he's already purchased and has in hand NTE's clone of the ICL8038, that doesn't help him a whole lot.

Using that function generator IC to simply generate a 500Hz sinewave is really quite a waste though, I'll have to agree.