ADC quantizer question.

On Oct 9, 2:33&#4294967295;am, "m26k9" <maduranga.liyan...@gmail.com> wrote:
> Hello,
>
> I am looking for some facts or specifications about an ADC quantizer.
> Firstly I want to know if it possible for quantizers to dynamically change
> their resolution? or is it fixed for a quantizer.
>
> If the quantizer can actually change its resolution, I would be very
> grateful if somebody could direct me to a site or a article about this
> mechanism. Specifically;
> 1) The connection between resolution and sampling rate
> 2) Resolution and power consumption.
>
> Any wisdom or reference is greatly appreciated.
> Thank you.

I haven't had a chance to read any of the references posted here, so
this may have been described, but one easy way to change the
resolution of an ADC is to use a successive approximation type
converter and only digitize as many bits as you need.  The converter
has to be designed to handle the max number of bits you require.  You
improve both speed and power by converting fewer bits.  Of course this
is not as fast or power efficient as a converter designed for fewer
bit since the comparison operation can go faster and use a lower power
comparator if you design it for less resolution.

Rick

>I haven't had a chance to read any of the references posted here, so
>this may have been described, but one easy way to change the
>resolution of an ADC is to use a successive approximation type
>converter and only digitize as many bits as you need.  The converter
>has to be designed to handle the max number of bits you require.  You
>improve both speed and power by converting fewer bits.  Of course this
>is not as fast or power efficient as a converter designed for fewer
>bit since the comparison operation can go faster and use a lower power
>comparator if you design it for less resolution.

Some ADCs will let you set the full scale to be between two external
references, rather than GND to AVDD.  It all depends on what is really
wanted.