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Looking for compact 13-bit ADC or ready ALaw codec

delphi-learner
on
Hi,

I'm creating a device that will convert audio signal to digital using ALaw.

That is why I need:
- ready ALaw chip that has built-in ADC and outputs ready 8bit samples. It is very important that this chip can be used with sample rates above 8KHz (eg. 16KHz).
or
- ADC converter that outputs 13 bits samples (or more) and can run at above 8KHz

I need something that is reliable, compact in size and with low power consumtion.

I will be very happy if someone can recommend me a solution that he/she has already used.

Thanks in advance to all,
Borislav
Comment
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max 1132 is a 16 bit adc up to 200ksps, and could be what you need.
If you are looking at a complete solution (adc + uc/dsp), take a look to cypress PSoC: http://www.cypress.com/?id=1353
They are a cpu with many analog and digital blocks, and you can try various kind of adc solutions (flash, sar, ..) and digital communication ports (i2c, spi, uart)... this could be a valid solution...

Hope that helps.

Author

Commented:
Thank you for both suggestions!

I will read some more about max1132 and will get back. At first glance It looks very promising.

Thanks.

Author

Commented:
Max1132 seems to be exactly what I need but for one thing: it looks like that it cannot output ALaw samples.

Is there some other chip that can directly give me ready ALaw samples at anything above 8KHz. That would be my perfect solution.
I've searched around but it seems a too specific requirement.
In my opinion the perfect solution would be an high resolution ADC and a Lookup table to perform the a-law compression - it's a static filter, so it is very simple to implement it - in hardware [with vhdl] and in software. You have only to pre-calculate the lookup table.
if n is the ADC resolution, and m the output resolution, you require 2^(n+m) bits to make the lookup table.

Hope that helps.

Author

Commented:
Thanks for the help.

I appreciate it.