Four-phase charge pump circuit

A four-phase charge pump circuit, comprising:

• a plurality of boosting stages, driven by a four-phase clock signal, wherein each of the boosting stages comprises two branch charge pumps, and each of the two branch charge pumps comprises:
• a main pass transistor, a first end of the main pass transistor serving as a first node of the branch charge pump, and a second end of the main pass transistor serving as a second node of the branch charge pump, wherein the first node and the second node of the branch charge pump are connected to a previous boosting stage and a next boosting stage of the boosting stage respectively;
• a pre-charge transistor, a first end and a second end of the pre-charge transistor being coupled to a control end of the main pass transistor and the first node of the branch charge pump respectively, and a control end of the pre-charge transistor being coupled to the second node of the branch charge pump;
• and
• two capacitors, coupled to the control end of the main pass transistor and the first node of the branch charge pump respectively,
• wherein at least one of the boosting stages further comprises:
• two auxiliary start-up transistors, a first end and a second end of each of the two auxiliary start-up transistors being coupled to the control end of the main pass transistor and the first node of one of the two branch charge pumps respectively, and a control end of each of the two auxiliary start-up transistors being coupled to the control end of the main pass transistor of one of the two branch charge pumps.