Patent ID: 7595684

Claim:
The 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 is provided with a first voltage setting circuit that has a plurality of resistive elements of a resistance value of (½) n of a resistance value which is to be a reference and a plurality of gate transistors connected to a plurality of the resistive elements, and gradually sets the voltage by switching and controlling a plurality of the gate transistors in response to a digital data of a binary code to switch a combination of a plurality of the resistive elements, and a second voltage setting circuit that has a plurality of resistive elements of the same resistance value as a resistance value which is to be a reference and a plurality of gate transistors connected to a plurality of the resistive elements, and gradually sets the voltage by switching and controlling a plurality of the gate transistors in response to a digital data of a thermometer code comprising a plurality of bits 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.