專利摘要：
A half-bridge resonant bidirectional DC-DC converter circuit comprising a half-bridge buck-boost converter and a resonant DC-DC converter. The half-bridge buck-boost converter is coupled to an external DC power source to achieve a wide input voltage range. The resonant DC-DC converter is coupled to the half-bridge buck-boost converter to act as a later stage circuit of the half-bridge buck-boost converter. The resonant DC-DC converter is used to control the direction of the bidirectional power flow and respond to the half-bridge buck-boost converter under a fixed frequency mode to convert the input of the half-bridge buck-boost converter to an induced current.