analog pin selection

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KeYp_290406
Level 4
Level 4

I have a project with 9 inputs (pots) to the adc via hardware mux and 9 capsense inputs. This is just the analog portion of the project. Is there any reason not to interleave the pin selection on these? I have a routing that works that does this. I have placed all of these on the left side gpio section. This is convenient for external connections. I want to check to see if it matters whether or not I place all of this on one side or if it's better to do the adc and mux on the left and all capsense on the right.

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HeLi_263931
Level 8
Level 8
100 solutions authored 50 solutions authored 25 solutions authored

One issue you might run into is that you can couple in unwanted noise from the CapSense pins into your analog inputs. This is something you need to look for.

   

There is an AppNote from Cypress regarding board design: http://www.cypress.com/?rID=39677 which might be helpful for you. Also look at the related notes (AN58304, AN58827) for hints regarding pin selection and analog routing.

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HeLi_263931
Level 8
Level 8
100 solutions authored 50 solutions authored 25 solutions authored
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KeYp_290406
Level 4
Level 4

Thanks

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ETRO_SSN583
Level 9
Level 9
250 likes received 100 sign-ins 5 likes given

And this user guide -

   

 

   

www.cypress.com/

   

 

   

Regards, Dana.

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