The PI37xx is a series of high efficiency, wide input range DC-DC ZVS-Buck-Boost regulators integrating controller, power switches, and support components, all within a high density System-in-Package (SiP). The PI37xx requires only an external inductor and a minimal number of capacitors, to form a complete DC-DC switching mode buck-boost regulator. The high switching frequency reduces the size of the external filtering components, improves power density, and enables very fast dynamic response to line and load transients. The PI37xx regulator sustains high switching frequency up to the rated input voltage without sacrificing efficiency and supports large DC-DC conversion ratios. The device can also be configured to operate in constant current mode.