Can anyone out there help me with the subject of using guard rings
     around op amp inputs to minimize leakage at the high impedance nodes?
     I will be using an FR-4 PCB, multilayer, PTH technology. From what
     I've read, it is suggested that the guard rings be placed on every
     layer. This begs the question: "How do I then connect traces to the
     node being guarded?". Also, any traces that do connect to the guarded
     node and then run outside of the ring are now subject to the same
     leakage that the original node was.

     Any help would be appreciated.

     Max.P.Harris
     Hardware Design Engineer
     Lockheed Martin Canada, Inc.

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