Cheap Simultaneous ADC?

[DrStu]

Hi all,

I'm working on a microphone array project which requires sampling signal from multiple mics at the same precise moment.

Specs:
-2 to 4 channels
-the ADC conversion speed is not important for me
-minimum 10 bits resolution
-Sampling frequency - 10k to 20kHz

Has anybody come across any low-cost ADC that does this? I'm looking for the cheapest solution to this, and any suggestions will do From what i've found so far, gettting a seperate microcontroller chip (which has two adc that supports simultaneous adc) seems cheaper than a dedicated adc chip.

Thx

 

[dknguyen]

Yep, getting two small MCUs is likely cheaper and getting two ADCs in the same MCU synchronized so they sample at the same time is also easy...but getting the same thing to happen in ADCs spread among different MCUs is trickier and less reliable, especially if they are running different code or the same code that is not always synced.

However, do you really need them to "simultaneously sample" for your audio sampling application? After all, even a multiplexed microcontroller ADC can jump between channels at 1MHz whereas the bandwidth of audio is only 20kHz. If you're sequentially sampling 4 channels at 1MHz when the signal bandwidth in each channel is only 20kHz, all 4 samples are pretty much simultaneous already since there's going to be almost no change in a 20kHz signal in the 1us it takes to jump to the next channel (3us for the time between the time the first channel is sampled and the 4rth channel is sampled).

 

[Mikebits]

I don't know the price but here is a 8 channel simultaneous sample A/D.
AD7606 | 8-Channel DAS with 16-Bit, Bipolar, Simultaneous Sampling ADC | All A/D Converters | Analog to Digital Converters | Analog Devices

 

[JenGiman]

Look here **broken link removed** There are finished examples with AD7606 data acquisition with frequency 10kHz, 20kHz and 100kHz.

 

[Nigel Goodwin]

7 year old thread closed - moderator.