• State
  • Locked Locked
  • Replies 3 replies
  • Subscribers 34 subscribers
  • Views 863 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.

485 power line communication. - SN65HVD96

Jin-Suk Choi
Intellectual 2290 points
Other Parts Discussed in Thread: SN65HVD96, TIDA-00527

Hi~ All.

Customer looking for power line communication which can support around 10W Load. (about 12V/1A load)

I found SN65HVD96 application note as below it looks mostly like what customer looking for.

http://www.ti.com/lit/an/slla336/slla336.pdf  

But, what is maximum power capacity can support with that solution? can it cover 12V/1A load?

And what is consideration for inductor? (like inductor value.....).

Any advice would be welcome.

Thanks.

  • 0
    TI__Mastermind 20820 points

    Hi Jin-Suk,

    We have done a reference design for power over RS-485 and it can be found here.

    To calculate appropriate values for L and C you should know:

    The frequencies you want to attenuate or "block". An easy way might be to do a fourier analysis of your signal with an oscilloscope and check the higher energy frequencies contained. You can calculate the -3dB roll-off frequency using the following formula:

    You will also need to terminate the bus with 120ohm termination resistor at both ends. Be aware of the current rating of your inductors, resistors, and caps as you will to support a lot of power. Please review the documentation contained in the TI design and let me know what other questions you have?

  • 0 in reply to Michael Peffers
    TI__Intellectual 2290 points
    Hi~ Michael. Thanks for your feedback. I can calculate according to your equation as above and how can I calculate proper rated current? When I study TIDA-00527 document, there is no specific comment on inductor current rate. Should I get inductor rate by try and error? Do you think 00527 application can support 10W application? I'm still concern this approach is right way or not.
  • 0 in reply to Jin-Suk Choi
    TI__Mastermind 20820 points
    Hi Jin,

    The inductor needs to be rated for the expected current (i.e. 1A) and the capacitor needs to be rated for the expected voltage (i.e. 12V).