Patent ID: 7772919

Claim:
A charge pump circuit comprising: a plurality of charge pumps each having their outputs connected in parallel, each charge pump receiving a plurality of clock signals, a clock signal oscillator for providing the plurality of clock signals, the clock signals being out of phase, each charge pump having an output (VCP) that is coupled to the output of the at least one other charge pump, further comprising a first capacitor in each charge pump, the first capacitor being charged by a switching circuit receiving said clock signals to charge the first capacitor to a voltage between a supply voltage and a reference potential, and further comprising a second capacitor coupled in series with the first capacitor, the second capacitor provided between a first terminal (IN) of the charge pump and a second terminal (OUT) of the charge pump, wherein the first terminal (IN) of the charge pump is connected to a second terminal (OUT) of another charge pump and the second terminal (OUT) of the charge pump is connected to the first terminal (IN) of another charge pump, and wherein when the first capacitor is charged by said switching circuit, the second capacitor is charged by its connection to another charge pump, the switching circuit connecting a first terminal of said first capacitor to the supply voltage thereby elevating a second terminal of said first capacitor to an elevated voltage, the second terminal of the first capacitor being connected to a first terminal of the second capacitor, and thereby elevating a second terminal of the second capacitor to a further elevated voltage elevated above the elevated voltage on the first capacitor, the further elevated voltage on the second terminal of the second capacitor being provided to the charge pump output.