How to run CDCE72010 by External Clock

Devang Bhavsar

Prodigy 20 points

Other Parts Discussed in Thread: CDCE72010

Hello,

I am trying to run CDCE72010 by External clock, rather than its VCXO 491.52 MHz.

I need to generate 10 MHz, 20 MHz & 40 MHz frequencies from it.

Help me out.

Thanks In Advance. . .

over 11 years ago

0 Madhu Balasubramanian over 11 years ago

TI__Expert 4400 points

Are you trying to synchronize the CDCE72010 to an external clock or do you want to use the device as a buffer/distributor? What is the external clock frequency?

If the external clock frequency is clean and is a nice multiple of 40MHz, then you can apply it to the VCXO_IN pins of the CDCE72010 and use its internal dividers to get the 3 clocks you need.

If you want to clean the external clock which could be dirty or if it is not a nice multiple of 40MHz, then you need to use a 40MHz VCXO to generate the 3 clocks you need.

Alternately, we have other devices with internal VCO that can be used for this purpose. Please let me know what's the requirement and intent and we can recommend the most appropriate device.

0 Devang Bhavsar over 11 years ago in reply to Madhu Balasubramanian

Prodigy 20 points

Hello,

Thank you Madhu.

I am trying to interface FMC150 ADC/DAC card with Xilinx Virtex 6 FPGA.

This card contains CDCE72010 module to generate a jitter free clock and i want to use CDCE72010 as clock distributor.

Untill I know it has fixed VCXO of 491.52 MHz, so i am applying a clean external clock of 640 MHz, a multiple of 40 to generate required frequencies.

Is that a proper way?

Thank you.

0 Madhu Balasubramanian over 11 years ago in reply to Devang Bhavsar

TI__Expert 4400 points

In this case, remove the VCXO and then apply your clean external clock into the VCXO_IN pins. Then you can use the internal dividers to generate your frequencies.

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How to run CDCE72010 by External Clock