• State Resolved
  • Locked Locked
  • Replies 4 replies
  • Subscribers 21 subscribers
  • Views 389 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.

LMK1D2102: SE to DE Conversion

Chandra Prakash
Prodigy 70 points
Part Number: LMK1D2102

Hello team,

I wanted to use LMK1D2101 to convert single ended clock(0.8 Vpp Clipped Sine Wave generated from ASVTX-13-A-19.200MHZ) to differential LVDS Clock. Is it possible to use this device for this purpose ? If yes, can you please some sample schematic which may give me an idea about how to use this device in this configuration. Thanks in advance.

Regards

  • 0
    TI__Mastermind 20900 points

    Hello Chandra,

    you can use this circuit:

    VIH/VIL are the top and bottom levels of the clipped sine waveform measured at the LMK1D21xx input pin.

    Vth can be generated with a resistor divider.

    regards,

    Julian

  • 0 in reply to Julian Hagedorn
    Prodigy 70 points

    Hello Julian,

    Thanks for your response. I have few Queries:-

    1)Does any kind of biasing needs to be provided at the positive input terminal ? Or in general, apart from the things shown in this diagram, is there need for any other external passives to be added?

    2) What is the role of Vref in this case?  Is there any need for it to be connected to the the negative terminal ?

  • +1 in reply to Chandra Prakash
    TI__Mastermind 20900 points

    Hi Chandra,

    1. No need for biasing. You will set the comparator threshold on the negative input pin with Vth (note, Vil/Vih needs to be measured at the LMK1D input pin or take VOH/VOL from the XO datasheet). Other terminations are not required. I would place a 0 ohm Rs first. You may want to ask the XO vendor for the output impedance, that you can match Rs + output impedance to 50 Ohm (or your PCB trace impedance).

    2. Vref is not used in this case. You can leave that pin floating.

    regards

    Julian

  • 0 in reply to Julian Hagedorn
    Prodigy 70 points

    Hello Julian,

    Thanks for the clarification.

    Am I correct in saying that Vref is used in AC coupled differential application to set common mode in them?

    Regards