Patent attributes
In order to resolve a problem of the conventional technique in which there is a charge pump capacitance which is not used when a boosting method of the charge pump is changed, in a charge pump circuit unit, a connection switching terminal selects a power source voltage, a logically-inverting buffer gate and a capacitor to conduct an operation of boosting the power source voltage so as to be twice the power source voltage, and a connection switching terminal outputs the boosted voltage as a boost control voltage. In a charge pump circuit unit, a connection switching terminal selects the boost control voltage outputted from the charge pump circuit unit, and a logically-inverting buffer gate and a capacitor conduct an operation of boosting the inputted voltage so as to be 3×VDD. An internal voltage is generated by outputting the boosted voltage to an internal power line via a NMOS transistor.
