Patent ID: 6949971

Claim:
A reference voltage generating circuit comprising: voltage outputting means for outputting a reference voltage corresponding to a difference between a band gap reference voltage and an input voltage; a first resistor having one end that is coupled to the output of the voltage outputting means; first variable resistor means having a plurality of second resistors that are serially coupled between the first resistor and a ground voltage, for providing the input voltage of the voltage outputting means with a first trimming voltage that is inputted to one and of selected one of the plurality of the second resistors in response to decoded signals for trimming the reference voltage; second variable resistor means coupled in parallel with the first variable resistor means and having a plurality of third resistors coupled serially between the first resistor and the ground voltage, the third resistors having different resistances from the second resistors, for providing the input voltage of the voltage outputting means with a second trimming voltage that is inputted to one end of selected one of the plurality of the third resistors in response to the decoded signals for trimming the reference voltage; and selecting means for selectively providing the first trimming voltage or the second trimming voltage to the input voltage of the voltage outputting means.