Patent ID: 8013588

Claim:
A reference voltage circuit for generating a reference voltage, comprising: a first power supply terminal; a second power supply terminal; a current supply circuit that has an input terminal to which a current is input, and a first output terminal and a second output terminal from each of which a current determined based on the current flowing through the input terminal is output; a first resistor; a first non-depletion mode metal oxide semiconductor (MOS) transistor of a first conductivity type, the first MOS transistor having a gate connected to the first output terminal, a source and a back gate that are connected to the first power supply terminal, and a drain connected to the first output terminal via the first resistor, the first MOS transistor operating in weak inversion; a second non-depletion mode MOS transistor of the first conductivity type, the second MOS transistor having a gate connected to a connection point between the first resistor and the first MOS transistor, a source and a back gate that are connected to the first power supply terminal, and a drain connected to the input terminal, the second MOS transistor having an absolute value of a threshold voltage of the second MOS transistor smaller than an absolute value of a threshold voltage of the first MOS transistor, the second MOS transistor operating in weak inversion, wherein a value of the threshold voltage is independent of structural variations in the first resistor and wherein a difference in the threshold voltage of the first and second MOS transistors is independent of structural variations in the first resistor; and a second resistor across which the reference voltage is generated, the second resistor being provided between the second output terminal and the first power supply terminal.