In a Dickson type charge pump in which a plurality of serially connected diodes sequentially respond to anti-phase 50/50 clock cross over or overlapped (.phi.1, .phi.2), efficiency of the charge pump is increased by providing with each diode a charge transfer transistor in parallel therewith between two adjacent nodes, and driving the charge transfer transistor to conduction during a time when the parallel diode is conducting thereby transferring any residual trapped charge at one node through the charge transfer transistor to the next node. Operating frequency can be increased by providing a pre-charge diode coupling an input node to the gate of the charge transfer transistor to facilitate conductance of the charge transfer transistor, and by coupling the control terminal of the charge transfer transistor to an input node in response to charge on an output node to thereby equalize charge on the control terminal and on the input node during a recovery period.
A booster circuit of a two-step booster structure is manufactured by NMOS single channel processes and has two basic booster circuits to raise a gate voltage of a charge transfer transistor. The gate voltage of the transistor is first raised at one basic booster circuit, and this raised voltage is further raised at the other basic booster circuit.
A single pump stage of a multi-stage charge pump couples a first low-voltage NMOS transistor in series with a first low-voltage PMOS transistor between charge transfer capacitors. A second low-voltage NMOS transistor is coupled between the gate and the source of the first NMOS transistor. A second low-voltage PMOS transistor is coupled between the gate and the source of the first PMOS transistor. Respective boost voltages are applied to gates of the first NMOS transistor and the second PMOS transistor to minimize threshold voltage losses. A stabilizing capacitor is connected between the first NMOS transistor and the second PMOS transistor.
Provided is an electronic device including a charge pump circuit whose circuit structure is simple and boosting efficiency is high. The charge pump circuit uses MOSFETs as charge transfer elements and has a structure in which a voltage of a gate of a charge transfer MOSFET is controlled to a predetermined level based on a dividing voltage caused by a first resistor connected between a source and the gate thereof and a second resistor connected between a drain and the gate thereof and a clock pulse for on/off control of the charge transfer MOSFET is supplied to the gate through a capacitor.
