Abstract: A multi-level LLC resonant converter with a wide output voltage range is proposed for the rear stage DC-DC of the on-board charger for electric vehicles (EVs). To achieve a higher level than the input voltage, one more half-bridge and auxiliary transformer is introduced with the control of pulse width modulation based on fixed-frequency phase-shift to extend twice the voltage gain range. The presented scheme avoids the restriction of gain range on resonance parameters under traditional frequency modulation (FM) control, and simplifies the parameter design process. Furthermore, by operating under the nature resonant frequency, the converter can realize ZVS of MOSFETs and ZCS of rectifier during the full charging process and a high efficiency can be achieved. A prototype with input of 380V and output power of 3.3kW is built to verify the feasibility of the proposed configuration and control scheme. The experiment results show that the converter provides a charging range of 250~420V for the traction battery, and the peak efficiency reaches 97.1%.