PCMD3140: PDM Routing

Can you please send me your schematic.

We do not have a schematic yet.

Please let me know what information you need to answer this question.

Is it something like this?

That is correct. Do you have any concerns with signal integrity?

I am not sure i have a great answer for you. If the PDM Clock wire to the Mic is some kind of twisted cable then there shall be distributed capacitance that

appears on the pin  .. Some cables create 50pf per foot. For 50cm cables or 2 foot cables and that might mean a 100 p load.

The PDM Clocks drive 2.4ma in 20p capacitive load in 18ns. For much larger capacitive loads you might want to put a buffer on the clock that can drive a higher output

current..

We are not running on a twisted cable. Could we perhaps use both PDMCLK_GPO1 and GPIO1 as individual buffered clocks?

Hi Daniel,

Sanjay is out of office until Wednesday so responses may be delayed. My advice would be to run a separate clock buffer to each destination. 

Brian

You could try a buffer such as 74LVC1G126GV ..