Decoupling and unused pins

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Anonymous
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for the CYD36S72V18, what are your recommendations for power supply decoupling and for handling unused pins?

   

Thanks,

   

Rich

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AjayB_76
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Not sure if you have had a look at our design guide for FullFlex devices - http://www.cypress.com/file/151216/download

   

It has the status of each of the pins which are not in use. 

   

For power supply- we recommend to have a decoupling capcitor for every pin and a bulk capacitor for every set of power rails. If there is a space constraint, we recommend to do a power integrity analysis to get the optimal value of bulk/decoupling capacitors array.

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AjayB_76
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Not sure if you have had a look at our design guide for FullFlex devices - http://www.cypress.com/file/151216/download

   

It has the status of each of the pins which are not in use. 

   

For power supply- we recommend to have a decoupling capcitor for every pin and a bulk capacitor for every set of power rails. If there is a space constraint, we recommend to do a power integrity analysis to get the optimal value of bulk/decoupling capacitors array.

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Anonymous
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Hi Ajai,

   

Thanks for your help.  I had found the design guide.

   

I guess I did not ask my first question very well.  Let's say I am using the left data ports as inputs only and that I need only 70 of the 72 bits.  What should I do with the two unused bits - tie them high via a resistor, tie them to ground or leave them open?

   

With respect to decoupling, do you recommend any particular value capacitors?

   

Thanks,

   

rich

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