I am constructing a hearing aid for my bachelor degree project. This hearing aid will consist of a microphone with a Nordic Semiconductor nRF2460 2.4 GHz transmitter, and a receiver of samë model with a speaker. This device should filter out any unwanted frequencies outside of speech, that is anything outside of 1-5 kHz. We want to sample at 12 kHz. I and my group are designing the PCB's and power supply ourselves. For simplicity we want mostly digital signals on our PCB's. Therefore we want to use the ADMP441 which has an ADC included with an I2S interface. Our transmitter and receiver (which are the same IC), support 16 bit I2S. The SSM2529 will be our DAC and amplifier stage, and also the filter stage.
The question is, can I use the ADMP441, which supports 24 bit, to send a 16 bit signal to my 16 bit compatible transmitter?
Nordic Semi told me this might prove difficult, as the nRF2460 operates at 256xFs.
We're rethinking our whole design because of soldering problems with very small components.
We're thinking about the AD1934 as DAC and AD1871 as ADC. It would seem that the nRF2460 demands a sampling rate of 32 kHz (waiting for confirmation from Nordic).
Question: Can I operate the AD1934 and AD1871 at Fs = 32 kHz with a clock at 256xFs? I checked out the datasheets, but it's all a bit confusing to me which requirement precedes the other.