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Observer
Observer
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Registered: ‎08-26-2020

Zynq7000 LVDS Powerconsumption

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Hello,

 

I am working with a Zynq7000- XC7Z014S.

If I use Bank 34 for LVDS with external 2.5V, is it only a reference or is it also used for driving LVDS outputs? Especially I am asking because of the power supply of the external 2.5V. 

 

Best regards

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Xilinx Employee
Xilinx Employee
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Registered: ‎11-30-2007

VCCAUX is not VCCO.  I was trying to show that differential input buffers (LVDS) are powered by VCCAUX, in part, which is a separate supply.

Please utilize the Xilinx Power Estimator and enter the IO Tab cells appropriately reflecting the 3 LVDS input pairs and 2 LVDS output pairs as well as the interface clock frequency.  You will also want to enter the rest of your design to properly estimate power.  When complete, you will use the Summary Tab to view the various power supply rails and required current.

forums_xpe_lvds.png

forums_xpe_summary.png

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Xilinx Employee
Xilinx Employee
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Registered: ‎03-07-2018

Hi @Nizlas 

I am not able to understand your query very well.

It seems you can find your answer in https://www.xilinx.com/support/answers/43989.htmlhttps://www.xilinx.com/support/answers/40191.html

Regards,
Bhushan

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Observer
Observer
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Registered: ‎08-26-2020

Hi @bpatil,

thanks for your reply. I have to admit, that my query might not have been very clear. However, I am quiet new here, so please give me a second try:

I am using LVDS_25 on Bank 34 with an external 2.5V reference. To do my power estimation, I would like to know, whether the LVDS_25 is driven by the 2.5V reference or by some internal power supply. 

If it is driven by the external reference, how high is the energy requirement for each LVDS_25 pair?

 

Best regards

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Xilinx Employee
Xilinx Employee
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Registered: ‎11-30-2007

I am assuming that you are powering VCCO_34 = 2.5V and the LVDS pair is an input?

Are you utilizing the 7 Series and Zynq-7000 Xilinx Power Estimator (XPE)?

Have you referenced the Xilinx Power Estimator User Guide (UG440; v2020.1)?

forums_ug440_table_1-3.png

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Observer
Observer
287 Views
Registered: ‎08-26-2020

Yes, it is VCCO_34 and I would like to use 2 LVDS pairs as output and 3 pairs as input. 

Is VCCO_34 in my case VCCAUX in XPE? Or where can I find the external power needs in XPE ?

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Xilinx Employee
Xilinx Employee
281 Views
Registered: ‎11-30-2007

VCCAUX is not VCCO.  I was trying to show that differential input buffers (LVDS) are powered by VCCAUX, in part, which is a separate supply.

Please utilize the Xilinx Power Estimator and enter the IO Tab cells appropriately reflecting the 3 LVDS input pairs and 2 LVDS output pairs as well as the interface clock frequency.  You will also want to enter the rest of your design to properly estimate power.  When complete, you will use the Summary Tab to view the various power supply rails and required current.

forums_xpe_lvds.png

forums_xpe_summary.png

View solution in original post

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Observer
Observer
258 Views
Registered: ‎08-26-2020
So my external 2.5V has to provide nearly 100mW? That's way more than I expected.
However, good to know and thanks for your help.
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