I have played with several of the signal generator chips: ICL8038,
XR-2206 and the MAX038.

I think all of them are going to be marginal generating less than 0.5%
distortion even with some tweaking.

For instance the XR-2206 is specified as having 0.4% distortion
TYPICAL with adjustment and 1.5% maximum when adjusted!

The ICL8038 is even worse 0.8% typical when adjusted. (There is no
maximum spec.)

The MAX038 is also only specified for typical distortion. Its spec.
is 0.75% adjusted.

I think that the MAX038 is the easiest to work with although I think it
is also much more expensive than the other two.



Ben Langhals wrote:
>
> I'm working on an application where I need to generate a sine wave and
> sweep its frequency.  I want to use a pic to control the process of the
> frequency sweep (most of the chips I've seen take an analog control voltage
> to adjust the frequency).  The range of frequencies I'm interested in is
> from 1 to about 35 kHz.  I want a low distortion wave (no more than .5%,
> esp in the lower part of the range) Two of the best contenders I've come up
> with are the exar 2206 and max 038 that can be found at
>
> http://www.exar.com/products/xr2206.html
>
> http://dbserv.maxim-ic.com/quick_view2.cfm?pdf_num=1257
>
> Anyway, I was just getting a feel for if anyone has used these guys in a
> similar application, or knew of a better option.  Whats easiest to
> interface with a PIC?
>
> Ben Langhals