| 摘要 |
PROBLEM TO BE SOLVED: To provide a comparator and an A/D converter, with which high-speed operation is enabled by using a differential amplifier. SOLUTION: An OTA circuit composed of NMOS transistors 16 and 17, a capacitor 18 and current sources 19-22 is provided between a differential couple composed of NMOS transistors 1 and 2 and NMOS follower transistors 9 and 10 comprising an output buffer circuit, a compensating current sCcV0, which is equal to a current flowing to capacity CGD between the gate and drain of the transistor in the differential couple, in the opposite direction, is generated by the OTA circuit and the current to flow to capacity CGD between the gates and drains of the transistors 1 and 2 of the differential couple is canceled, so that the differential amplifier of high gain and wide band to be operated with a low power supply voltage can be provided. By using this differential amplifier, the comparator capable of high-speed operation and the A/D converter are provided.
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