PURPOSE: To realize a high-speed division, by constituting a dividing circuit with a voltage-current converter, a voltage-resistance converter and an error amplifier.

CONSTITUTION: The voltage X(V) is supplied to the voltage-current converter 10 through the terminal 21. If the conversion gain is referred to as K10, the output current I10(A) becomes K10.X. The current I10 is supplied to the voltage-resistance converter 12 having an internal resistance R12 to obtain voltage G25=I10.R12 at the input/output terminal 24. When the input G24 and Y are supplied to the error amplifier 11 having a sufficiently large gain, Y-G24=O is obtained. As a result, R12=Y/(K10.X) is obtained. If the conversion gains of the voltage-resistance convertes 12 and 13 are set at K12 and K13 respectively, V11=R12/K12 and R13=K13. V11 are obtained for the output voltage V11 of amplifier 11 an the internal resistance R13 of converter 13. Accordingly R13=K13/(K10.K12) Y/X is obtained, and R12 gas a value proportional to a division Y/X. Then a result of division is obtained by measuring the value of R13. As a result, a time constant circuit can be excluded to realize a high-speed division.