• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 32 subscribers
  • Views 576 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

CLC001: Using CLC001 to drive 100 ohm twisted shielded pair

Robert Curtis
Intellectual 430 points
Part Number: CLC001

Hello,

My question relates to the output 75 ohm resistors used  in the CLC001 application notes.  If the device is being used to drive a 100 ohm twisted pair cable, should the 75 ohm load resistors be replaced with 50 ohm load resistors?  Will changing the resistor load adversely affect the CLCL001 output performance?

Thanks for any help you can give,
Rob Curtis

  • 0
    TI__Mastermind 29655 points
    Hi Robert,

    You are correct. I presume the figure you are referring to is Figure 6 (Twisted Pair Cable, DC-coupled) and Figure 7 (Twisted Pair Cable, AC- coupled). Assuming you drive a 100-ohm twisted pair cable, there should be 50-ohm load resistors for each output polarity.

    The only side effect I anticipate by driving a 50-ohm output is that, since the output is current mode, the driver amplitude for each output will be about 2/3 the amplitude when the resistor load is 75-ohm. Note though, that you may have different requirements for amplitude when driving differentially across the twisted pair.

    Voltage amplitude can be adjusted by modifying the R_REF resistor value. This value can be lowered to increase the drive voltage, and the value can be increased to decrease the drive voltage amplitude.

    Thanks,

    Michael