Little PICs with hi-res A-D ?

[Eeyore]

Andre Majorel wrote:

Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote:
Anthony Fremont wrote:
Eeyore wrote:
Anthony Fremont wrote:
David L. Jones wrote:

12F683 is the pick of the bunch:
http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en010115
only 10bit ADC, Microchip haven't figured out how to do
12 bit yet.

I agree, that's the best 8 pin PIC I know of. Don't be
fooled by the 12F, it's still a 14 bit core like the 16F
series.

How about a couple with 'windowing' ? Can that be done to
extend the resolution ?

I guess you could try oversampling. If you really need more
than 10 bits, maybe an external chip? You really haven't
provided much information on your ADC performance
requirements.

Doesn't need to be fast for one if that's what you mean. It's
for scanning some level controls on a pro-audio product.
That's why we want better than 10 bit resolution.

Don't know what kind of control this is but IME, a rotary pot
with a 15 mm knob can be reliably set to about 1/350th of the
range. That's less than 9 bits.

Ah, well we'd be scanning 100mm stroke audio faders too.

You might be wondering why but have you ever heard of a
phenomenon called 'zipper noise' ?

Wouldn't that be better addressed by some averaging and
interpolation in software ? That would get rid of both zipper
noise and jitter.

It might be but the volume control element the guy had in looks to have it's
own problems now, so it looks like Plan B or C now.

Graham