pmod I2S

[sandeepsan]

Hi,

I am newbie to Zybo board. I am currently looking for a microphone which can work on Zybo board with following requirements

Microphone requirement: Omnidirectional, -/+ 1 dB: 100 Hz to 8KHz -/+2 dB: 50Hz to 20KHz

ADC requirement: 16-bit with sampling rate support >=16KHz

I have looked at couple of available pmod I2S modules from Digilent website. They seem to have 12 bit A/D converter.

Can anyone please suggest possible microphone for above requirements?

Thanks for the help.

Best Regards

Sandeep

[D@n]

Have you looked at the PmodMIC3?  While it only contains a 12bit ADC, that ADC will run at 1Msps.  That means you can get your extra 4-bits back if you want a sample rate less than 1Msps/16.  (i.e. run at 1Msps, average 16 samples, get 4-extra bits of value as a result.)  62.5ksps is more than sufficient for any audio task you might come across, so this is likely to meet your requirements, no?

Dan

[sandeepsan]

Hi,

Thanks for the reply. I have gone through PmodMIC3. As per my understanding, you meant 4 samples needs to be recovered by averaging?Please correct me if wrong. The averaging effect can introduce distortion in underlying audio task(feedback from audio task implementers) before reconstructing the signal. So it is recommended for me to use 16bit ADC with a microphone. Please let me know if there are any 16 bit ADC that can be interfaced with Zybo.

Thanks for the help.

Best Regards

Sandeep

[D@n]

Yes, I meant four bits would be recovered by averaging.  Yes, this effect can introduce distortion depending upon the environment.

At this point I think all I can say is that there are still many ADC's that _can_ be interfaced with a Zybo, although I am not in a position to state whether Digilent sells any that might meet your needs.  The ones I know about are listed here, and I would wager you've already been through that list by now.

Dan

[sandeepsan]

Hi Dan,

Thanks for the quick reply. Yes I have gone through the list.

Best Regards

Sandeep

[JColvin]

Hi Sandeep,

Unfortunately, Digilent does not sell any microphones that meet your requirements nor am I aware of an ADC that meets your needs that will nicely interface with the Zybo.

I'm sorry that I couldn't be of more help.

Thanks,
JColvin