Abstract: The disclosure provides a multilevel port under-voltage protection circuit with flying capacitor, comprising: a first circuit unit having first to fourth power switches sequentially connected in series, wherein the first circuit unit is arranged a positive terminal and a negative terminal of a DC input port and each of the switches can tolerate a reverse current; a first flying capacitor having a first terminal connected to the common node of the first power switch and the second power switch in series, and a second terminal connected to the common node of the third power switch and the fourth power switch in series; and a first shunt element connected in antiparallel to the first power switch or the fourth power switch, wherein a pulse peak current tolerated by the first shunt element is greater than the reverse current tolerated by the first power switch or the fourth power switch.

Abstract: The disclosure provides a multilevel port under-voltage protection circuit with flying capacitor, comprising: a first circuit unit having first to fourth power switches sequentially connected in series, wherein the first circuit unit is arranged a positive terminal and a negative terminal of a DC input port and each of the switches can tolerate a reverse current; a first flying capacitor having a first terminal connected to the common node of the first power switch and the second power switch in series, and a second terminal connected to the common node of the third power switch and the fourth power switch in series; and a first shunt element connected in antiparallel to the first power switch or the fourth power switch, wherein a pulse peak current tolerated by the first shunt element is greater than the reverse current tolerated by the first power switch or the fourth power switch.