Patent ID: 7323926

Claim:
A charge pump circuit, comprising: a first pump stage, including a first sub-pump coupled to a first pre-charge MOSFET transistor, wherein the first sub-pump is used to pull down a gate of the first pre-charge MOSFET transistor to a first sub-negative voltage while the first pre-charge MOSFET transistor is off to thereby increase pre-charge efficiency of the first pre-charge MOSFET transistor; and a second pump stage coupled to the first pump stage, the second pump stage including a second sub-pump coupled to a second pre-charge MOSFET transistor, wherein the second sub-pump is used to pull down a gate of the second pre-charge MOSFET transistor to a second sub-negative voltage while the first pre-charge MOSFET transistor is off to thereby increase pre-charge efficiency of the second pre-charge MOSFET transistor.