A tracker circuit configured to provide a variable supply voltage to a power amplifier (PA) circuit is disclosed. The tracker circuit comprises a predefined state machine circuit comprising a plurality of states mapped in accordance with transitions associated with a predefined mapping scheme. In some embodiments, the plurality of states of the state machine circuit identify one or more operational modes associated with the tracker circuit, wherein the one or more operational modes comprises one or more voltage levels respectively associated therewith. In some embodiments, the one or more operational modes comprises at least two active operational modes. In some embodiments, a transition between the one or more operational modes of the tracker circuit is dictated by a decoding of a digital selection signal received from a digital communication interface associated therewith.