Patent attributes
A low power charge pump is disclosed. A pump driving node of a first pump stage is selectively coupled to a pump driving node of the subsequent pump stage. Subsequent to a transfer of charge from a first pump stage to a subsequent stage, the first and subsequent pump driving nodes are coupled. Residual charge on a first stage pump driving node is thereby transferred to a subsequent pump driving node. Subsequent to the transfer of charge from the first pump driving node to the second pump driving node, the nodes are uncoupled. By selectively coupling a first pump stage to a pump driving node of the subsequent pump stage, the first pump driving node may pre-charge the subsequent pump driving node, thereby reducing the energy that must be provided by clock driving circuitry to produce a positive-going transition of a driving clock. Advantageously, pre-charging energy is taken from the first stage, reducing the energy that was heretofore dissipated by clock driving circuitry during a negative-going clock signal transition. In this novel manner conversion efficiency of a charge pump device may be beneficially increased, providing enhanced low power performance.
