A first and second node configured to couple to a load. A current source is adapted to drive a first current to the load through at least one of the first and second nodes. A first switch is coupled to the at least one of the first and second nodes. The first switch is adapted to interrupt the first current. A sense circuit is configured to monitor whether a second current is provided by the load after the first current is interrupted. The sense circuit provides an output that corresponds to a value of the second current and that indicates a type of the load.