Here we go let's make a High-Quality Function Generator

Thread Starter

be80be

Joined Jul 5, 2008
2,051
This is the deal I got a nice outdated XR-2206

I'm starting like this Circuit. Anything you see I need to do to make it better.

Screenshot from 2018-01-29 19-31-19.png
Next problem I want use a 12 volt wall wart like this.

Screenshot from 2018-01-29 20-09-48.png
 
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RichardO

Joined May 4, 2013
2,271
Is your output referenced to the artificial ground? If so then you won't be able to supply much power into your load -- not even a milliamp. :(
 

Papabravo

Joined Feb 24, 2006
16,514
The XR-2206 is kind of a crappy function generator. There is a good deal of distortion over 20 kHz. in the sine wave. The triangle has rounded and bumpy corners, and lastly the square wave has numerous artifacts, espacially at higher frequencies. I built one of these a long time ago (ca. 1978) and seldom used because it was just a piece of crap.

If you really need one, you should buy one or rent one.
 

DbLoud120

Joined May 26, 2014
82
XR2206.png XR2206.png Hi be80be, I found this schematic some time ago. Not sure who author is. I was interested enough that I purchased an XR2206 but have yet to test circuit.

Seeing your post makes me want to at least breadboard circuit to see how well it might work. I will post results when I have something to see.

I do have oscilloscope to check waveforms.
 

Thread Starter

be80be

Joined Jul 5, 2008
2,051
I have the parts and a scope I just wanted to start with the best circuit.
The only thing I don't have is a split supply. Was trying to come up with a work around for that I tested what I posted just don't think it will output
The power needed
 

atferrari

Joined Jan 6, 2004
4,387
AD9834CRU something like that

YES!! YES!! YES!,

I suspect my 10 MHz Siglent función generador is built around one of these.

My experience: the stumbling block is not other than the output filter.

Wait and you will see comments telling it is easy to design. But not for me.

I would like to write the code to program it. Really.
 

Standisher

Joined Jan 16, 2015
129
There's a short series of videos (by 'Scullcom Hobby Elecronics') on Youtube about his project to build a function generator using the XR-2206, an arduino nano and a 7 segment display. I copied his design almost to the letter, including the enclosure he used (except that I added a Function Counter which he never did get round to adding as originally planned) and it does work quite well, particularly in the audio ranges. I can only get to about 150kHz before the signal becomes quite distorted. My unit does also tend to 'drift' a bit after a while but I don't know if that is a feature of the chip or as a result of my construction :oops:. Anyone interested in playing with this chip may also like to have a look at the Exar XR-2206 Function Generator Databook which can be found in pdf format here . A picture of my completed version of Mr Scully's project is attached.
 

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KL7AJ

Joined Nov 4, 2008
2,229
This is the deal I got a nice outdated XR-2206

I'm starting like this Circuit. Anything you see I need to do to make it better.

View attachment 144689
Next problem I want use a 12 volt wall wart like this.

View attachment 144694
Excellent! I JUST happened to find one of those chips last week in my ancient parts bin! I understand the chip is no longer in production, but plenty of NOS sources.

It's a wonderful chip.....I don't know WHY so many manufacturers discontinue absolute winners like this.

Nice job. I'm building a local oscillator for a low frequency receiver with this.
 
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