3 Replies Latest reply on Apr 25, 2016 12:22 AM by rahb

    Capsense maximum Proximity sensing

    joe.sag

      Hi there,

         

      I am using CapSense on a circular board and my aim is to enable wake-on approach from as far away as possible. I have done a first design but I am not totally satisfied yet with the result. Would be great if I could get some additional tips on how to make my design better.

         

      Here is what I have done:
      - the board is circular, 133mm in diameter (~5.2 inches) and has 4 layers
      - I put the circular sensing electrode (1.6mm/63mil width) on the circumference of the top layer (nothing else on the other layers)
      - the driven shield electrode is placed right behind it (1mm/40mil width with 1mm/40mil space to the sensing electrode, circular and on top and bottom layer)
      - the rest of the circuitboard (all the components plus guard ring) with 1mm/40mil space behind the shield electrode.

         

      I studied the available pdfs from Cypress and also the schematic and layout of the MBR3 eval kit. Is there something I could do better layout wise to get a longer proximity sensing distance?

         

      Thanks a lot for your help!

         

      Regards,
      Josef