• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 21 subscribers
  • Views 497 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.

CDCE62002: CDCE62002 usage for ADS5409

Gaurav Agrawal
Intellectual 650 points
Part Number: CDCE62002
Other Parts Discussed in Thread: ADS5409

Hi,

We plan to use the clock gen CDCE62002 for generation of 900MHz (LVPECL) for the 900MSPS ADC ADS5409, along with a 100MHz LVDS clock output. Please help with some design queries as below:

1) ADS5409 lists input clock amplitude as 2Vp-p typical, while the CDCE62002 LVPECL differential out is shown as max 870 mV. Shall the ADS5409 input be driven with sufficient swing in this case?

2) We use LVPECL output of CDCE with each line terminated to GND through 150 Ohm res, followed by AC coupled capacitor connections to ADS5409 Clock input. Please confirm if ok.

3) Only primary reference of CDCE shall be used, having options of feeding a 100 MHz LVDS input OR a 25MHz LVCMOS TCXO input.

Regards

Gaurav

  • 0
    TI__Genius 9920 points

    Hi Gaurav,

    1) CDCE62002 shows "LVPECL Hi-PERFORMANCE OUTPUT" |VOD| ranges 670 ~ 950 mV, that's absolute swing for one line. For 2 lines differential pk-pk, that's 1.34 ~1.90 V. They could work with ADS5409,  refer to Figure 27 in ADS5409 datasheet.

    2) Connection is correct.

    3) CDCE62002 could accept LVDS or LVCMOS reference clock. Notice external terminators should be different to match Register 0 setting.

    Best Regards,

    Shawn