PURPOSE: To decrease the capacity ratio of a capacity integrator by reducing gradually the voltage transferred to an integrated capacity connected between a negative input terminal and an output terminal of an operational amplifier with every operation of a switch which works on a clock decided by the digit number of a digital value notation number.
CONSTITUTION: When switches SW3 and 4 are turned on, the input signal voltage is sampled/held 2. This voltage is transferred with switches 5 and 6 turned on in the timing of a shorter cycle than a sampling clock S with the signal of weight coefficient of each digit of the digital value notation number delivered from a weight coefficient generator 3. Then the output voltage of an operational amplifier 1 is added to the so far output voltage in a ratio between capacities CA' and CB. Then switches SW7 and 8 are actuated with the timing clock equal to that of the generator 3 to discharge the electric charge of the capacity CB'. Thus the voltage of the capacity CB is set at one-to-sum value of capacities CB, and CB'. Then the voltage of a prescribed integration coefficient is delivered when the SW4 is turned on.
UENO NORIO
KANEKO KAZUHIRO
Next Patent: SEAL IMPRESSION COLLATING SYSTEM