A method and apparatus is provided for using a single power supply in a
dual mode fashion. A ringing signal is received. A waveform power supply
signal based upon the ringing signal. An unbalanced output buffering
function upon the signal to be conditioned using an unbalanced buffering
circuit. Performing the unbalanced output buffering function includes
switching between a plurality of power levels of the waveform power
supply signal to maintain a predetermined maximum voltage across a
plurality of devices relating to the unbalanced buffering circuit.