US Patent 7969230 Voltage generating circuit

A charge pump provides high boosting efficiency with low power loss even with a heavy load. Plural charge transfer switches are connected in series forming two lines of charge transfer circuits operated by out-of-phase clock signals. Capacitors are connected to each of nodes in the charge transfer circuits. The charge transfer circuits include a first control unit, a second control unit, and a voltage comparison output unit. The second control unit includes a switch unit configured to selectively feed a signal from a previous-stage node or a later-stage node to the gate of a charge transfer switch in the second control unit, depending on the phase of the clock signal.