| 摘要 |
This invention provides a comparator circuit which outputs a stable waveform without oscillation even if a gradient of a change of a comparison input signal is small and determines a magnitude of the comparison input signal within a predetermined threshold value regardless of the increase/decrease direction of the comparison input signal. A comparator circuit 100 comprises a capacitative element 4 which is charged or discharged corresponding to a difference of potential between a comparison input signal IN and a reference input signal REF, an analog buffer portion 5 which outputs high level if the voltage is above a threshold voltage Vth and low level if it is less than the threshold voltage Vth, an edge detecting portion 7 which detects leading and trailing edges of the analog buffer portion 5 so as to output an up signal UP and a down signal DOWN and a charge pump portion 8 which charges a capacitative portion corresponding to the up signal UP and discharges the capacitative portion corresponding to the down signal DOWN.
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