Voltage generation circuit and semiconductor memory using the same

Abstract

The voltage generation circuit having a standard voltage generation circuit, a reference voltage, a minimum voltage setting circuit, and a voltage setting circuit that gradually sets voltage by switching a plurality of the gate transistors to switch a combination of resistive elements. The voltage generation circuit includes a differential amplifier that has one input terminal connected to the reference voltage generated by the standard voltage generation circuit and another input terminal connected to the minimum voltage setting circuit. The differential amplifier has an output node showing the result of a difference voltage of the inputs. The voltage generation circuit includes a pump control circuit that outputs a control signal controlling a charge-pump motion, based on the differential voltage, and a charge pump circuit that sets up and outputs the voltage by the control signal.

1 . A voltage generation circuit comprising:
 a standard voltage generation circuit that generates a reference voltage;   a minimum voltage setting circuit that sets a minimum voltage;   a voltage setting circuit that has a plurality of resistive elements and a plurality of gate transistors connected to a plurality of the resistive elements, and gradually sets voltage by switching a plurality of the gate transistors to switch a combination of a plurality of the resistive elements;   a differential amplifier that has two input terminals and one output node, one input terminal is connected to the reference voltage that is generated by the standard voltage generation circuit, another input terminal is connected to the minimum voltage setting circuit and the voltage setting circuit that has a plurality of resistive elements and a plurality of gate transistors connected to a plurality of the resistive elements, and the output node shows the result of the difference voltage of these two inputs;   a pump control circuit that outputs a control signal controlling a charge-pump motion, based on the differential voltage; and   a charge pump circuit that sets up and outputs the voltage by the control signal.