| 摘要 |
PURPOSE:To realize a circuit system which is capable of a highly precise analog- digital conversion by giving the compensation to the offset voltage of the integrating circuit. CONSTITUTION:Switch circuit 11 switches analog input voltage VIN to be converted into the digital quantity, positive reference voltage VR and analog earth voltage VGA each through control circuit 12, and the voltage to be selected is integrated via integrating circuit 13. This voltage is compared with threshold voltage VC at comparator 17, and thus comparison signal CO is delivered to be supplied to circuit 12. At circuit 12, initial reset signal IR, start signal SP and the output of counter circuit 18 are received, and switch control signals phi1-phi3 plus phi10-phi17 of switch circuits 11 and 19 are delivered. On the other hand, circuit 18 receives the signals delivered from circuit 12, counts clock pulse CP to deliver the signals to the control circuit, and also delivers the converted digital quantity. |
