A device configured to draw current from one of a PSTN source and a battery source depending on a mode of operation of the device is disclosed. In a preferred embodiment, the device includes a circuit that is configured to draw current from the PSTN source during a first condition and from the battery source during a second condition. Preferably, the circuit is defaulted to draw current from the battery source. The first condition can be associated with an off-hook condition. The second condition can be associated with an on-hook condition.