An integrated converter and method are provided that combine an onboard charger and a low voltage direct current converter. The integrated improves the charging efficiency of the battery of a vehicle and supplies the high density power to an electronic device load. The charging efficiency of the high voltage battery and electricity transmitting efficiency to the low voltage converter is improved using the integrated converter. Furthermore, the low voltage converter receives high density power since the low voltage converter is input with a substantially stable voltage from the integrated converter.