The present invention is directed at circuit for controlling a voltage applied to an output voltage terminal from a first voltage level supplied by an input voltage terminal comprising a first switch and a second switch connected in series between said input voltage terminal and a common terminal; a transformer, having a primary side and a second side, connected with said first switch on the primary side and to said output terminal on the secondary side; wherein when said first switch is closed and said second switch open, said first voltage level is supplied to said output voltage terminal; and wherein when said first switch is open and said second switch is closed, a second voltage level is supplied to said output voltage terminal.