• State TI Thinks Resolved
  • Locked Locked
  • Replies 2 replies
  • Answers 1 answer
  • Subscribers 23 subscribers
  • Views 385 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Original question:

LMK05028: 10MHz Output from 10MHz OR 1PPS Input

LMK05028: How to distribute clock to many TIDA-01454

Mikel Culla
Prodigy 110 points
Part Number: LMK05028
Other Parts Discussed in Thread: TIDA-01454, LMK5C33216, PCM1864,

Hello,

I would like to have an array of 9 TIDA-01454 Circular Microphone Matrix sample at the same time, but I am not really keen on clocks. So I want to know if this LMK05028EVM is what I am looking for, maybe another product would be better for my project.

In the project it is really important for all the matrix in the array to sample exactly at the same time, so in order to achieve this, clocks must be synchronized between them. But for this I face at least 2 problems:

1. There are 9 CMBs, is it possible to distribute the same clock to 9 devices?

2. The CMBs, will be at a distance up to 5 metres from each other, so this might be a problem when it comes to clock times, attenuation and reflections. So what kind of connection should I use taking in account that  the CMB works with Dupont wires?

Thanks,

Mikel

  • 0
    TI__Genius 12705 points

    Hello,

    The LMK05028 or LMK5C33216 can provide more than 8 synchronized output clock signals and the LMK5C33216 includes digital and analog delay features for adjusting relative timing of outputs. How this would interface to the PCM1864 will need to consult with fellow product line

  • 0 in reply to Liam Keese
    TI__Mastermind 46805 points

    Hi Mikel,

    Since the limitation here is distance, I wouldn't worry about getting the proper connector on both sides. It would too difficult to find a long enough cable that could interface with both (unless you really wanted to make one yourself). I'd instead identify solder points that you can use to break off from the board. For instance on the LMK there are 0ohm resistors you can remove to isolate the jack from the circuit and run from there. On the mic board you could solder to the other side of the dupont headers. Each run should have a termination resistor (33ohm or so to start) to get rid of reflections but since it's buffered I don't expect that to be a huge issue, especially since I2S is a relatively slow protocol. Best practice would still be to use the termination resistors anyway.

    Best regards,

    Jeff