I am building a system using multiple PDM MEMS microphones with a high acoustic overload point (>130dB) like Invensense INMP621, Infineon IM69D130 or Knowles SPH0644HM4H-1 (see diagram https://imgur.com/a/h5Z96). At the main pcb an Analog Devices ADAU 7002 will convert the PDM signal to TDM, to be processed by a dsp like ADAU1701. Each microphone will have a cable of max 1m to it. The recommended lengths for PDM lines seem te be under 20cm, so I was wondering what are your recommendations for ensuring robust operation?
Some constraints are that I am constrained in the pcb size on the microphone end (making it hard to add more than a few passive components) and I cannot make differential pairs as I can only use one wire per line on the CAT cable.
Next to using a source termination resistor, I have seen suggestions of using series ferrite beads and clock buffers, but I was wondering what are your recommendations?
Thanks a lot!