Patent ID: 8829979

Claim:
A power-efficient multi-mode charge pump comprising: a first pumping circuit configured to provide at least one output voltage produced by a discharge sequence of a shared flyback capacitor; a second pumping circuit configured to provide a plurality of output voltages produced by a corresponding plurality of discharge sequences of said shared flyback capacitor; and a regulation circuit configured to: provide dynamic turn-on resistance control signals during a smooth transition sequence from said at least one output voltage to one of said plurality of output voltages, compare, at an increased clock rate, a first holding capacitor voltage to a first reference voltage, and a second holding capacitor voltage to a second reference voltage, and reduce a magnitude of a shared flyback capacitor voltage until said shared flyback capacitor voltage substantially equals one of said first reference voltage and said second reference voltage, wherein said increased clock rate is substantially equal to an integer multiple of a system clock rate and said control signal includes a number of bits, said number of bits being substantially equal to said integer multiple of said system clock rate.