Embodiments of negative pressure wound therapy systems and methods are disclosed. In one embodiment, an apparatus includes a housing, negative pressure source, circuit board, and one or more controllers. The circuit board can be supported by the housing and include a conductive pathway extending around at least part of a perimeter of a first side of the circuit board. The conductive pathway can be electrically coupled to an electrical ground for the circuit board. The one or more controllers can be mounted on the circuit board and activate and deactivate the negative pressure source.