Patent ID: 7595682

Claim:
A method for operating a multistage charge pump in a first mode and in a second mode, comprising: configuring the multistage charge pump so that N stages each including a supply node are enabled in the first mode, and so that less than N stages are enabled in the second mode including allowing the supply node in enabled stages to fluctuate at a level above a supply potential, and coupling the supply node in a disabled stage to the supply potential without voltage loss of a threshold voltage drop, and thereby decoupling the disabled stage from preceding stages in the plurality of stages; producing a first set of clock signals having a first clock frequency which changes according to a first function; producing a second set of clock signals having a second clock frequency which changes according to a second function wherein at least one of the first function and the second function is dependent on at least a power supply voltage, and at least one of the first function and the second function is dependent on at least temperature; and applying the first set of clock signals to a multistage charge pump to produce a charge pump output voltage in the first mode of operation and applying the second set of clock signals to a multistage charge pump to produce a charge pump output voltage in the second mode of operation.