In one embodiment, a boost-buck converter can include: (i) first and second switches coupled in series between input and an output of the boost-buck converter; (ii) a first inductor coupled to the input and third and fourth switches, where the third switch is coupled to ground, and the fourth switch is coupled to the output; (iii) a second inductor coupled to the output and a common node of the first and second switches; and (iv) a control circuit configured to control switching of the first, second, third, and fourth switches according to the input and output voltages, such that the boost-buck converter operates in at least one of: a buck mode and a boost mode.