Voltage stepup circuit for integrated semiconductor circuits

Abstract

A voltage stepup circuit having a plurality of setup circuit units connected in stages between an input voltage node and a stepup voltage node. Each circuit unit comprises at least two first and second MOS transistor T1 and T2. Each of first stepup capacitors is connected between a first clock signal supply node and a first connection node at which the drain and gate of a corresponding one of odd-numbered MOS transistors, of a plurality of MOS transistors connected in series through the plurality of stepup circuit units, are connected together. Each of second stepup capacitors is connected between a second connection node at which the drain and gate of a corresponding one of even-numbered MOS transistors of the plurality of MOS transistors connected together and a second clock signal supply node for supplying said second connection node with a second clock signal whose pulse width does not overlap in time with that of the first clock signal. A first clock amplitude control circuit limits the amplitude of the first clock signal to be supplied to the first clock signal supply node to a predetermined level and applies the first amplitude-limited clock signal to the first clock signal supply node. A second clock amplitude control circuit limits the amplitude of the second clock signal to be supplied to the second clock signal supply node to a predetermined level and applies the second amplitude-limited clock signal to the second clock signal supply node.