| 摘要 |
PURPOSE:To attempt reduction and improvement of accuracy of an offset voltage, by constructing a switch in which the offset voltage of a charge-equibrium type comparator changes polarity of a field-through error alternatively. CONSTITUTION:Comparing circuits in which capacitors CA and CB are connected to an invertor 1 respectively and in- and output ends of the invertor are short- circuited by switches SWA, SWB are connected in 2 steps, in the first step, 2 switches SW01, SW02 switching alternately the input voltage are connected. In a short-circuited switch of the 1st. step comparing circuit an NMOS switch is used and in the 2nd step, a PMOS switch is used for constructing polarities which repulse field-through errors of the switches. By this construction, a low offset voltage can be obtained in a stable manner.
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