Patent attributes
A multi-level boost apparatus. Voltage allocation among N first switches is achieved by arranging the N voltage dividing modules. It is prevented that the second one to the N-th one of the first switches break down and fail due to overvoltage. By arranging an (i−1)-th clamp branch at a common node between an (i−1)-th second switch and an i-th second switch, a voltage bore by the i-th second switch is clamped at a difference between a voltage across the fourth branch (namely, an output voltage of the multi-level boost apparatus) and a voltage across the corresponding clamp branch. The risk is avoided that a second one to the N-th one of the second switches break down due to overvoltage at an instant of being powered, in a case that the input voltage is low.