| 摘要 |
PURPOSE: The invention relates to an integrated circuit charge pump and more particularly to a charge pump with a single HVPMOS transistor as a main switch having coupled in parallel to its source and extended drain a bulk switch with fixed bulk connection. CONSTITUTION: An HVNMOS/HVPMOS switched capacitor charge pump(20), comprising: a charge stage for charging a first capacitive means and a pump stage for charging a second capacitive means, said pump stage coupled to said charge stage for transferring a charge of said first capacitive means to said second capacitive means, thereby raising the voltage potential of said second capacitive means to above the voltage potential of said first capacitive means, where a HVPMOS transistor(21) of said charge stage is coupled between a first input of said charge stage and a first terminal of said first capacitive means, and where a HVPMOS transistor of said pump stage is coupled between said first terminal of said first capacitive means and a first terminal of said second capacitive means; a bulk switch circuit for synchronously switching the bulk of said HVPMOS transistors of said charge stage and said pump stage to the voltage node of said HVPMOS transistors, said bulk switch circuit comprising serially coupled minimum HVPMOS transistors, each said minimum HVPMOS transistor having their drains coupled together, and where a bulk terminal of each of said minimum HVPMOS transistors is coupled to its respective source, where a first said bulk switch circuit is coupled in parallel to a drain and a bulk terminal of said HVPMOS transistor of said charge stage, where a second said bulk switch circuit is coupled in parallel to said bulk terminal and a source of said HVPMOS transistor of said charge stage, where a third said bulk switch circuit is coupled in parallel to a drain and a bulk terminal of said HVPMOS transistor of said pump stage; and where a fourth said bulk switch circuit is coupled in parallel to said bulk terminal and a source of said HVPMOS transistor of said pump stage.
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