Does I2S support sending multiple mic (around 20) channel data? If no, what is the limiting factor in supporting multiple mics?
Also, is there any way to send multiple channel data from different MICs in any other format other than TDM, if TDM on I2S doesn't allow more than certain number of channels?
It is a generic question and any hardware can be sited as an example. All I am after is that given any hardware what limits the maximum mic supported?
Mic stands for microphone.
Best Answer
I2S is sometimes used to carry multiple channels, particularly between ADC/DAC and CODEC devices. The standard is for two channels, as mentioned by colin in his answer, however you can send multiple datastreams with extra lines.
For example the Cirrus Logic CS42448 (datasheet) CODEC uses a single bit clock (SCLK) and LR select (LRCLK), and multiple data lines (SDIN/SDOUT). Each data line carries 2 channels, and their assignment (left, right, front, back etc) is entirely arbitrary. So yes, I2S can carry multiple channels (sort of abuse of the standard though).
However, would you want to use I2S to carry 30 channels? If its between audio processing ICs on the same board, maybe. More depends on what the devices expect (I2S, TDM, PCM etc).
If you are carry these audio signals along cables, then almost certainly I2S would be a mistake. It isn't designed for distances, and you'll have issues with signal integrity and phasing between clock and data lines.