| 摘要 |
Differential chopper type comparator including a switching circuit which switches between a reference signal and an input signal according to a connected first period and second period, first and second comparator circuits, and a differential comparator circuit differentially comparing the outputs of the first and second comparator circuits. Each of the first and second comparator circuits comprises a capacitor, an inverter serially connected to the capacitor, and a switch that short-circuits the input/output terminal of the inverter during the first period. The first and second comparator circuits operate in tandem such that the reference signal is input to the firs comparator circuit during the first period when the inverter is short-circuited, while conversely the input signal is input to the second comparator circuit during the first period when its inverter is short-circuited, with the reverse occurring with respect to the first and second comparator circuits during the second period. A comparison as between the size of the input and reference signals is accomplished by the first comparator circuit, and a comparison as between the size of the reference and input signals is accomplished by the second comparator circuit. The outputs of the first and second comparator circuits are then provided to the differential comparator circuit which produces a resultant comparative output effectively free of noise even when the environment is of a high noise level.
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