This paper presents a high-efficiency positive buck–

boost converter with mode-select circuits and feed-forward techniques.

Four power transistors producemore conduction andmore

switching losseswhen the positive buck–boost converter operates in

buck–boost mode. Utilizing the mode-select circuit, the proposed

converter can decrease the loss of switches and let the positive

buck–boost converter operate in buck, buck–boost, or boost mode.

By adding feed-forward techniques, the proposed converter can

improve transient response when the supply voltages are changed.