• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 34 subscribers
  • Views 723 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.

SN75176B: Power over differential line

Norbert Toth
Expert 1145 points
Part Number: SN75176B
Other Parts Discussed in Thread: TIDA-00527

Hi Folks,

First of all, sorry, if this is not the right forum for my question.

I have to plan a system / solution, where I have to generate PWM signals occasionally far from each other (~50m), but due to cost consideration, placing a CPU to everywhere is not an option. So I wanted to transmit my PWM signals trough differential lines, on  the same wire where the power goes for the receiver chip. I fond the TIDA-00527 reference design.

So my question is: what should I modify (which jumper path should I select) to transmit PWM signals around 2kHz with DutyCycle 1-99% and 12-24V on the same wire? Even somebody know alternative / cheaper / better solution?

Regards,

Norbert

  • 0
    TI__Mastermind 25705 points

    Norbert,

    I think the design idea should work for your application. What voltage swing of PWM signals do you transmit? The rule of thumb of choosing inductor value is to separate AC signal (data) from power (DC) far enough that they don't interfere with each other. The cut off frequency of LC network is 1/(2*Pi*sqrt(LC)). Taken C=10uF, 50mH inductor would generate a high pass filter with 200Hz cut off frequency. I think it would be low enough for your 2kHz data rate to pass. Please let me know if you have other questions.

    Regards,

    Hao