>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.

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

On Fri, 09 Oct 2009 13:03:06 -0400, Randy Yates <yates@ieee.org>
wrote:

>Eric Jacobsen <eric.jacobsen@ieee.org> writes:
>
>> On 10/9/2009 1:07 AM, Mikolaj wrote:
>>> On 09-10-2009 at 08:33:39 m26k9 <maduranga.liyanage@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.
>>>
>>> My first thought was oversampling,
>>> shortly it is changing resolution within increasing sampling rate
>>> (and there is a strict formula on that)
>>>
>>> Very, very good tutorial is here:
>>> http://www.lr.ttu.ee/irm/sideseadmete_mudeldamine/AD_MT_Tutorial.pdf
>>>
>>
>> I don't know who Walt Kester is, but I'm a fan!
>>
>> That's an excellent reference for all things having to do with ADC/DAC
>> technology and issues.
>
>It *is* a very nice reference. He looks like he was (or is) an Analog
>Devices engineer - probably the type that writes their application notes.  I
>guess these *are* application notes?

Hi Randy,
  you're right.

Some years ago I called Walt Kester to warn him 
of a rogue Interent site that illegally posted a copy 
of one of Walt's books.  He is a nice guy.

m26k9 might want to have a look at:

http://www.analog.com/processors/learning/training/design_techniques.html

See Ya',
[-Rick-]

Thank you very much for that text... it is indeed really good... many
concepts described nicely...

"Alexander Sotnikov" <sotnikov@scideco.ru> writes:

> Walt has been working at ADI for many years. He is the editor of Data
> Conversion Handbook and these tutorials are just the excerpts from
> there.

Ah! I have a 1986 copy of that book! It is quite excellent.

> You can find the whole book here:
> http://www.analog.com/library/analogDialogue/archives/39-06/analog_digital_conversion.zip

Thank you!
-- 
Randy Yates                      % "Though you ride on the wheels of tomorrow,
Digital Signal Labs              %  you still wander the fields of your
mailto://yates@ieee.org          %  sorrow."
http://www.digitalsignallabs.com % '21st Century Man', *Time*, ELO

>
>I don't know who Walt Kester is, but I'm a fan!
>
>That's an excellent reference for all things having to do with ADC/DAC 
>technology and issues.
>
>-- 
>Eric Jacobsen
>Minister of Algorithms
>Abineau Communications
>http://www.abineau.com
>

Walt has been working at ADI for many years. He is the editor of Data
Conversion Handbook and these tutorials are just the excerpts from there.
You can find the whole book here:
http://www.analog.com/library/analogDialogue/archives/39-06/analog_digital_conversion.zip

--Alexander

On pi&#4294967295;, 09 pa&#4294967295; 2009 19:03:06 in article news:<m3bpkgwldh.fsf@ieee.org>
Randy Yates wrote:
>>> Very, very good tutorial is here:
>>> http://www.lr.ttu.ee/irm/sideseadmete_mudeldamine/AD_MT_Tutorial.pdf
>>>
>>
>> I don't know who Walt Kester is, but I'm a fan!
>>
>> That's an excellent reference for all things having to do with ADC/DAC
>> technology and issues.
> 
> It *is* a very nice reference. He looks like he was (or is) an Analog
> Devices engineer - probably the type that writes their application notes.  I
> guess these *are* application notes?


Newer versions here: D/A Converters - Tutorials
http://www.analog.com/en/training-and-tutorials/tutorials/design-center/products/digital-to-analog-converters/da-converters/resources/index.html

Eric Jacobsen <eric.jacobsen@ieee.org> writes:

> On 10/9/2009 1:07 AM, Mikolaj wrote:
>> On 09-10-2009 at 08:33:39 m26k9 <maduranga.liyanage@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.
>>
>> My first thought was oversampling,
>> shortly it is changing resolution within increasing sampling rate
>> (and there is a strict formula on that)
>>
>> Very, very good tutorial is here:
>> http://www.lr.ttu.ee/irm/sideseadmete_mudeldamine/AD_MT_Tutorial.pdf
>>
>
> I don't know who Walt Kester is, but I'm a fan!
>
> That's an excellent reference for all things having to do with ADC/DAC
> technology and issues.

It *is* a very nice reference. He looks like he was (or is) an Analog
Devices engineer - probably the type that writes their application notes.  I
guess these *are* application notes?
-- 
Randy Yates                      % "Bird, on the wing,
Digital Signal Labs              %   goes floating by
mailto://yates@ieee.org          %   but there's a teardrop in his eye..."
http://www.digitalsignallabs.com % 'One Summer Dream', *Face The Music*, ELO

On 10/9/2009 1:07 AM, Mikolaj wrote:
> On 09-10-2009 at 08:33:39 m26k9 <maduranga.liyanage@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.
>
> My first thought was oversampling,
> shortly it is changing resolution within increasing sampling rate
> (and there is a strict formula on that)
>
> Very, very good tutorial is here:
> http://www.lr.ttu.ee/irm/sideseadmete_mudeldamine/AD_MT_Tutorial.pdf
>

I don't know who Walt Kester is, but I'm a fan!

That's an excellent reference for all things having to do with ADC/DAC 
technology and issues.

-- 
Eric Jacobsen
Minister of Algorithms
Abineau Communications
http://www.abineau.com