This document discusses, among other things, apparatus and methods for passing a signal in a power down state. An example switch device can include a first depletion-mode transistor configured to pass an analog signal between a first node and a second node in a first state and to isolate the first node from the second node in a second state, a control circuit coupled to a control node of the first depletion-mode transistor and configured to isolate the control node from a first supply input in the first state and to couple the control node to the first supply input in the second state, and a tracking circuit configured to couple the control node of the first depletion-mode transistor to the first node during the first state and to isolate the control node of the first depletion-mode transistor from the first node in the second state.