all the waveform generators are dying out

Hi I need a waveform generator, integrated in a circuit... I found bougth an old ICL8038 that I realize after too late it costs 9$ (a bit too much) and the reason is that it is out of production. I am a bit skeptic on building new design with something is already known is obsolete. So I checked around for "more modern" alternative.

I realize that the famous Max038 is also obsolete ("strongly not adviced" in the datasheet). NTE864 is expensive 30$

Then I found that exar produces the Xr8038 and the XR2206, but I haven't found on their website the XR8038 (start thinking is dying out even this).

So my conclusion is : It seems that after a while all the waveform generator become out of production ... the next dying will be the XR2206 (the last one seems in production).

I know how to make a square wave from a 555timer, but I was concerned about the precision, i.e. a specific IC for waveform generator like one the cited should be more reliable ? My concerns are linked to the fact that I am building a medical device, so precision and reliability matter. Please let me know your opinion.

Reply to
sunone
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Do you just need a square wave ??

What is the precision you need ? ( highest freq, lowest freq )

don

PS: Yes, I would use a PIC,AVR,MSP depending on the other requirements.

Reply to
don

Perhaps you could have a look at analog devices' AD9833 (Farnell, 5.71 EUR / 100). Otoh, building a medical device is a world by itself... you should carefully evaluate if 9$ is indeed too much.

Pere

Reply to
oopere

What sort of waveforms, how accurately and over what frequency range? The 8038 was only really good if you wanted a quick and dirty low parts count function generator with square, triangle and sine wave available simultaneously. Its sinewave shaper was only approximate to ~1% THD on a good day.

I don't think think the 8038 was anything to write home about in stability terms either ~250ppm/C or thereabouts. The humble 555 manages ~100ppm/C. Though the 555 drift with supply voltage is worse.

Regards, Martin Brown

Reply to
Martin Brown

Most modern signal genarators are done with DDS like the AD9833 mentioned,or FPGA mostly a combination of the both.

You can find some basic DDS signal generator examples on the web. Heres one by David Jones if your nice to him he may give you some pointers:).

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And another

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Reply to
Hammy

if you must be cheap and can stand the distortion, this has a 8038 clone in it

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note: finding good fets for that ap note may be difficult these days.

Steve

Reply to
osr

--
If a square wave is all you need, a cheap and easy way to get it is to
build a crystal oscillator using a CD4060 as shown on page 3-160 of:
 Click to see the full signature
Reply to
John Fields

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