摘要 |
PROBLEM TO BE SOLVED: To provide a logic circuit, an analog/digital (A/D) conversion circuit and the like with a small number of elements by utilizing a capacitive coupling circuit. SOLUTION: In the A/D conversion circuit having an input terminal to which an analog input is imparted, and an N-bits (N is a multiple number) output terminal to which a binary output is imparted, N unit circuits each including an input capacitor of which the one electrode is connected to the input terminal, a first inverter wherein the other electrode of the input capacitor is inputted, and a second inverter connected to the first inverter, are parallel provided. Outputs of the second inverters in the unit circuits are imparted to the respective output terminals, and further, an inverted output of the output corresponding to each unit circuit is fed back to the input of the first inverter in the unit circuit corresponding to a low-order bit via a feedback capacitor. A capacitive value of the feedback capacitor corresponding to the inverted output of an M-th (M is an integer) unit circuit from a most significant bit is 1/2M-fold input capacity of the unit circuit to which the output is fed back. COPYRIGHT: (C)2004,JPO&NCIPI
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