PURPOSE: To realize the voltage dividing ratio of 1/2 with higher accuracy than the accuracy of a voltage dividing ratio of a voltage dividing element by deciding an error of the final voltage dividing ratio depending on the product between the error of the voltage dividing ratio of the voltage dividing element and the error of the capacitance ratio of the 1st and 2nd capacitors.

CONSTITUTION: Switches 21, 24, 25 are turned on and switches 22, 23, 26, 27 are turned off in the 1st mode. Then the switches 23, 22, 26 are turned on and the switches 21, 24, 25, 27 are turned off in the 2nd mode. Furthermore, the switch 27 is turned on and the switches 25, 26 are turned off in the 3rd mode. The error of the voltage dividing ratio of voltage dividing output voltages Vout (error to 1/2) is a product between the error α of the resistance value and the error β of the capacitors. Thus, in considering that the voltage dividing circuit is realized by an integrated circuit and taking the errors as α=0.01 and β=0.01, the product αβ is 0.0001 and the error is compressed larger than the individual values α and β.