CDC7005: 2 Minutes question : How the VCXO_IN need to be used ?

Romain Magne

Part Number: CDC7005
Other Parts Discussed in Thread: LMK6P

Hi everyone,

I have a question about using the VCXO clock with the CDC7005. It seems it requires an LVPECL clock, but I'm not quite sure how it operates. I'd like to understand how to utilize it effectively. Additionally, does the VCXO input require a dedicated VCXO quartz or something else?

In my project to generate a 300MHz frequency from the CDC7005, does the VCXO clock need to be higher than the generated clock?

Any help or clarification would be greatly appreciated!

5 months ago

0 Kadeem Samuel 5 months ago

TI__Genius 15380 points

Romain,

This device requires an LVPECL VCXO as the input for generating an output clock. This is an example of such a device: https://www.crystek.com/specification/vcxo/CVPD-925.pdf

What are the swing requirements of your output clock? There may be a simpler device that you can use here.

If LVPECL and only a single output, then the LMK6P BAW oscillator can be used for generating this frequency: https://www.ti.com/product/LMK6P

Thanks,
Kadeem

0 Romain Magne 5 months ago in reply to Kadeem Samuel

Prodigy 20 points

Hi Kadeem,

Thank you very much for your response.

Since I posted the question, I've actually found my solution. I'll be using a VCTXO oscillator for the reference input and a VCXO with PECL output, providing a frequency range of 1 to 800 MHz.

This fulfills all my requirements.

Once again, thank you Kadeem for your reliability.

Clock & timing

Clock & timing forum

CDC7005: 2 Minutes question : How the VCXO_IN need to be used ?