Charge pump circuit with dynamic biasing of pass transistors

Abstract

A two-phase charge pump is provided that is controlled by first and second clock signals in phase-opposition. The charge pump has a sequence of cascade-connected stages. Each stage includes a capacitive element driven by one clock signal such that capacitive elements of adjacent stages are driven by different clock signals, a pass transistor that transfers electric charge to the capacitive element from the capacitive element of a previous stage, a first biasing circuit that enables the pass transistor during a first phase of the one clock signal, and a second biasing circuit that disables the pass transistor during a second phase of the one clock signal. Also provided is a two-phase charge pump having two branches that each include a sequence of such cascade-connected stages, with each stage of one branch having a corresponding stage in the other branch. A method of operating two-phase charge pumps is also provided.