An onboard charging module (OBCM), e.g., for a vehicle, is characterized by an absence of a transformer and includes an AC-to-DC voltage rectifier, DC-DC buck converter, DC-DC boost converter, DC link capacitor between the buck converter and boost converter, and solid-state devices. The devices include a diode and first and second switches having opposite open/closed switching states. The first and second switches are connected to a common rail of a DC bus, the first switch and diode are between the voltage rectifier and boost converter, and the second switch is between the link capacitor and buck converter. Third and fourth switches may be used on the opposite rail as the first and second switches. The OBCM is operable, via operation of the solid-state devices, to charge the HV-ESS via an AC power supply while maintaining current isolation. An electrical system includes the OBCM, DC bus, and HV-ESS.