An isolated bidirectional DC-DC converter is designed for a dual-output EV charger. Various DC-DC converter topologies are compared, including single-output converters and dual-output converters. Then one suitable topology is selected between the multiport CLLC converter and triple active bridge converter based on the simulation performances for the dual-output EV charger. Meanwhile, an investigation into the voltage regulation for a wide output voltage range is conducted with the research of interleaved buck converters. Finally, the system-level control of the EV charger is designed for different operation modes and the converter is modelled in PLEVS and simulated under different scenarios.