A switching transformer includes a primary circuit and a secondary circuit. The primary circuit includes a first input/output (I/O) terminal, a plurality of primary windings, and primary switching circuitry including at least one switch configured to selectively connect the plurality of primary windings in series or in parallel. The secondary circuit includes a second I/O terminal, a plurality of secondary windings, and secondary switching circuitry including at least one switch configured to selectively connect the plurality of secondary windings in series or in parallel.