Interference signal decoupling on a printed circuit board

摘要

A decoupling circuit on a printed circuit board is disclosed. The decoupling circuit comprises an electrical filter circuit electrically connected between an interconnect post and a ground land of the printed circuit board. The ground land is connected to a ground plane in the printed circuit board. The electrical filter shunts conducted interfering signals received at the interconnect post to the ground plane. Components of the electrical filter circuit and ground plane form a first receiver loop in which induced interfering signals can be generated. The decoupling circuit also comprises a second receiver loop comprising a conductive coating of an EMI shield conformingly adhered to surfaces of the decoupling circuit, and a conductive path of the first receiver loop. The second receiver loop is adapted to have induced therein a signal having a direction and magnitude sufficient to cancel interfering signals induced in the first receiver loop.