A switching circuit, comprising: - a charging sub-circuit ( 210, 410, 510, 610), having a first input end and an output end; - a switching sub-circuit ( 220, 420, 520, 620), having a first end, a second end and a control end, wherein the control end of the switching sub-circuit ( 220, 420, 520, 620) is connected to the output end of the charging sub-circuit ( 210, 410, 510, 610); - a functional sub-circuit ( 230, 430, 530, 630), connected to one of the first end and second end of the switching sub-circuit ( 220, 420, 520, 620), and the functional sub-circuit ( 230, 430, 530, 630) having a first node, wherein an operating voltage of the first node is higher than an input voltage of an input power supply (V in), wherein the switching sub-circuit ( 220, 420, 520, 620) comprises one or more NMOS switches, wherein the first input end of the charging sub-circuit ( 210, 410, 510, 610) is connected to the first node, wherein the other of the first end and second end of the switching sub-circuit is connected to the input power supply, and the charging sub-circuit further comprises a second input end connected to the input power supply, characterized in that: - the charging sub-circuit comprises a first diode, a second diode and a second capacitor, - the anode of the first diode is connected, as the second input end of the charging sub-circuit, to the input power supply, and the cathode is connected to the control end of the switching sub-circuit; - one end of the second capacitor is connected to the control end of the switching sub-circuit, and the other end is grounded; and - the anode of the second diode is connected, as the first input end of the charging sub-circuit, to the first node, and the cathode thereof is connected to the control end of the switching sub-circuit. - a charging sub-circuit ( 210, 410, 510, 610), having a first input end and an output end; - a switching sub-circuit ( 220, 420, 520, 620), having a first end, a second end and a control end, wherein the control end of the switching sub-circuit ( 220, 420, 520, 620) is connected to the output end of the charging sub-circuit ( 210, 410, 510, 610); - a functional sub-circuit ( 230, 430, 530, 630), connected to one of the first end and second end of the switching sub-circuit ( 220, 420, 520, 620), and the functional sub-circuit ( 230, 430, 530, 630) having a first node, wherein an operating voltage of the first node is higher than an input voltage of an input power supply (V in), wherein the switching sub-circuit ( 220, 420, 520, 620) comprises one or more NMOS switches, wherein the first input end of the charging sub-circuit ( 210, 410, 510, 610) is connected to the first node, wherein the other of the first end and second end of the switching sub-circuit is connected to the input power supply, and the charging sub-circuit further comprises a second input end connected to the input power supply, - the charging sub-circuit comprises a first diode, a second diode and a second capacitor, - the anode of the first diode is connected, as the second input end of the charging sub-circuit, to the input power supply, and the cathode is connected to the control end of the switching sub-circuit; - one end of the second capacitor is connected to the control end of the switching sub-circuit, and the other end is grounded; and - the anode of the second diode is connected, as the first input end of the charging sub-circuit, to the first node, and the cathode thereof is connected to the control end of the switching sub-circuit.