AVR-Chat

At 08:39 AM 7/29/2004, Mark Jordan wrote:

>On 29 Jul 2004 at 8:15, David VanHorn wrote:
>
>> You need to connect AVCC (always!), you need to supply an external
>> reference, or use VCC for ratiometric measurements (the internal reference
>> is pretty dodgy), you need to supply a cap on the ref pin.
>
>        Does the same apply to the ATMEGA8 ADC? I have used the internal
>reference without problems.

I suspect it's endemic to all micros, but I haven't checked the M8.
On the tiny-26's the "precision" reference of 2.5V was sitting at 2.7V.
10% error into a 10 bit A/D?   

>> Yes, it is successive approximation, at something like 200 kHz.
>
>        You can go up to 1MHz if you only need 8 bit precision.

I never tried "overclocking" it, never really needed to. 
I've heard others complaining about several bits of jitter, but I never saw that, just the expected 1 bit quantization errors.