CDCE6214-Q1: Zero Delay Buffer - External Feedback

Brian Hammerbacher

Part Number: CDCE6214-Q1
Other Parts Discussed in Thread: CDCE6214, CDCI6214

Hello,
I was looking at the CDCE6214 to act as a zero delay buffer, but I do not see how to configure the registers to allow that.

Using the TICS Pro tool, I could not work out how to set up the PLL so that the outputs would be the same frequency as the inputs with SECREF as the feedback.

The closest I could get is the incoming frequency divided by two.

Obviously I am missing something as you would need the same frequency to even use the external feedback.

Thank You,
Brian

over 3 years ago

0 Brian Hammerbacher over 3 years ago

Intellectual 285 points

I wanted to add that with the CDCI6214(which I think is pin compatible) using TICS Pro tool, it seems to function fine. The CDCE6214 when you set it to ZDM none of the multipliers work on the PLL page.

I'm not sure which one is incorrect.

Thank You,
Brian

0 vicente flores prado over 3 years ago in reply to Brian Hammerbacher

TI__Mastermind 29362 points

Good afternoon Brian,
CDCE6214 does support zero delay mode.

I believe your issue might be you're not selecting the correct Channel Muxes.

Default is PSA but changing the channel Mux REFCLK as shown for OUT3/4 does result in correct frequency.

Regards,

Vicente

0 Brian Hammerbacher over 3 years ago in reply to vicente flores prado

Intellectual 285 points

Hi Vicente,
I actually did see I could set it to refclk but was confused as the CDCI6214 seemed to use the PLL in ZDB mode. Doesn't setting them to REFCLK bypass the PLL? Is the delay elements that align the phase not part of the pll?

Thanks,

Brian

+1 vicente flores prado over 3 years ago in reply to Brian Hammerbacher

TI__Mastermind 29362 points

Hi Brian,
Sorry you're correct it does bypass the PLL. There appears to be a GUI error since the PFD becomes the VCO freq when ZDM is activated.
One workaround that appears to work is setup the configuration with ZDM OFF and then activating ZDM mode once you have appropriate outputs like in the second attachment. The Registers updates correctly. Will have to ask someone to look into this GUI issue.

Regards,

Vicente

Clock & timing

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CDCE6214-Q1: Zero Delay Buffer - External Feedback