JPS6349828B

PURPOSE:To constitute a titled circuit so that it is not influenced by offset voltage and accuracy of a feedback capacity, by accumulating such charge as negates input offset voltage in advance in the feedback capacity, and discharging this charge in order to a suceeding integrator. CONSTITUTION:At first, a control signal generating circuit 39 is operated so that switches 35-1, 35-2 and 38 between preceding and succeeding inverted input terminals and output terminals, and only switches 33-1, 33-2 between preceding feedback capacities 31-1, 31-2 and the succeeding inverted input terminals become a connected state, and input offset voltage of each leading operational amplifiers 30-1, 30-2, and succeeding input offset voltage are applied to the preceding feedback capacities 31-1, 31-2. When the accumulation time has ended, all the switches are set to an off-state once, and the switches 35-1, 35-2 are operated so that the inverted input terminal and the output terminal of the preceding operational amplifiers 30-1, 30-2 become a conducting state. Subsequently, the switches 33-1, 33-2 are controlled so that the charge accumulated in the preceding feedback capacities 31-1, 31-2 is selectively discharged to the succeeding integrator by use of the succeeding switch 38.