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Re: ball-hours

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rickman wrote:
> On 10/16/2014 4:37 PM, Joerg wrote:
>> rickman wrote:
>>> Each processor is very low power when running flat out, just 5 mW.  But
>>> they almost never run flat out.  Because they are asynchronous they
>>> spend most of their time stopped when they draw 0.0875 uW, yes, that's
>>> less than a tenth of a uW for each processor or just 12 uW for the whole
>>> chip.  The processors respond to stimuli in just nanoseconds, not 100's
>>> or even 10' but single digit nanoseconds.
>>>
>>> Trust me, power will not be a problem with this part.  It is a very
>>> different beast to program however.
>>>
>>
>> I wonder how that company is doing. I read about their products years
>> ago but never seen any in schematics and I get to see a lot of new stuff
>> because some of my daily bread is EMC remedy.
> 
> All kidding aside, your application may be one that is well suited to
> the GA144.  With your data rates the GA144 can certainly keep up
> processing wise.  The CODEC I/O would be no problem at all.  The I2S
> interface can be bit banged by 700 MHz processors.
> 
> The only issues would be designing the algorithms to perform the signal
> processing.  There is no math library that I know of.  So you would need
> to design your own.
> 

That is something we really want to avoid. Funding for this project is
not unlimited but most of all there isn't an infinite amount of time. So
we'd like to rely of pre-canned packages for complex FFT, phase
calculations, IIR/FIR filtering, Goertzel and so on.


> I think the chip would be running at a small fraction of a watt.  With
> every node running flat out the power consumption is under a watt.
> 

That would of course be nice but 5W would be fine as well. Meaning we'll
need a QFP with a heat sink pad underneath.

> 
>> What I mean is that ADCs on processors generally cannot hold jitter low
>> enough to truly deliver a 96dB SNR. I found that even 12 bits on-chip is
>> already a serious challenge.
> 
> Not that it is a serious contender, but ADI makes an old ARM7 chip with
> 16 bit ADCs on board, not sure how many, I don't think it was five, it
> may have been four.  It was only 33 MHz and doesn't have any of the DSP
> like instructions.  But they designed it with the analog in mind.  I
> seem to recall they marketed it with their ADC families rather than with
> their processors.
> 

That's too slow and also ADCs on board of CPUs usually have subpar noise
behavior, IME. I don't know that processor but don't want to take the
chance because you won't discover until at the very end of the project.

> 
>>   18 bits of what exactly?  I have seen lots of devices with 24
>>> bits but only 96 dB SNR.  Do you need 108 dB SNR?  You won't get that
>>> from the GA144 ADCs at 48 kHz.
>>>
>>
>> True 96dB across DC-15kHz would be enough.
> 
> The GA144 ADCs are just not quite there.  Like I said, they get 15 bits
> at 48 kHz sample rate.  I don't recall how slow the sampling needs to be
> to get 16 bits (96 dB nominally).  Likely it is about 12 kHz.
> 

In order to reach 96dB the ENOB has to be 16 bits at max speed, meaning
in reality most ADC would have to provide 18 bits.

-- 
Regards, Joerg

http://www.analogconsultants.com/

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Re: ball-hours rickman <gnuarm@gmail.com> - 2014-10-15 00:25 -0400
  Re: ball-hours bruce.person@gmail.com - 2014-10-14 23:51 -0700
    Re: ball-hours rickman <gnuarm@gmail.com> - 2014-10-15 03:15 -0400
  Re: ball-hours Joerg <news@analogconsultants.com> - 2014-10-15 05:36 -0700
    Re: ball-hours rickman <gnuarm@gmail.com> - 2014-10-15 16:22 -0400
      Re: ball-hours Joerg <news@analogconsultants.com> - 2014-10-15 16:12 -0700
        Re: ball-hours rickman <gnuarm@gmail.com> - 2014-10-15 22:48 -0400
          Re: ball-hours Joerg <news@analogconsultants.com> - 2014-10-16 11:21 -0700
            Re: ball-hours rickman <gnuarm@gmail.com> - 2014-10-16 15:24 -0400
              Re: ball-hours Joerg <news@analogconsultants.com> - 2014-10-16 13:37 -0700
                Re: ball-hours rickman <gnuarm@gmail.com> - 2014-10-16 17:42 -0400
                Re: ball-hours Joerg <news@analogconsultants.com> - 2014-10-17 07:14 -0700
                Re: ball-hours rickman <gnuarm@gmail.com> - 2014-10-17 14:03 -0400
                Re: ball-hours Joerg <news@analogconsultants.com> - 2014-10-17 12:03 -0700
                Re: ball-hours rickman <gnuarm@gmail.com> - 2014-10-17 15:23 -0400
                Re: ball-hours Joerg <news@analogconsultants.com> - 2014-10-17 12:44 -0700
                Re: ball-hours rickman <gnuarm@gmail.com> - 2014-10-17 18:37 -0400
                Re: ball-hours rickman <gnuarm@gmail.com> - 2014-10-16 20:59 -0400
                Re: ball-hours albert@spenarnc.xs4all.nl (Albert van der Horst) - 2014-10-17 08:43 +0000
                Re: ball-hours rickman <gnuarm@gmail.com> - 2014-10-17 13:53 -0400
                Re: ball-hours Joerg <news@analogconsultants.com> - 2014-10-17 07:50 -0700
        Re: ball-hours Raimond Dragomir <raimond.dragomir@gmail.com> - 2014-10-15 20:42 -0700
          Re: ball-hours rickman <gnuarm@gmail.com> - 2014-10-16 01:50 -0400
            Re: ball-hours Raimond Dragomir <raimond.dragomir@gmail.com> - 2014-10-16 00:49 -0700
              Re: ball-hours rickman <gnuarm@gmail.com> - 2014-10-16 05:14 -0400
            Re: ball-hours Joerg <news@analogconsultants.com> - 2014-10-16 11:58 -0700
        Re: ball-hours "Elizabeth D. Rather" <erather@forth.com> - 2014-10-16 08:32 -1000
          Re: ball-hours rickman <gnuarm@gmail.com> - 2014-10-16 15:32 -0400
          Re: ball-hours Joerg <news@analogconsultants.com> - 2014-10-16 13:45 -0700

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