| 摘要 |
PURPOSE:To prevent the large variation of ON-resistance due to the input signal by making it possible to alter the back gate potential of the MOSFET used in the switch connected to an operational amplifier, an integrating condenser and a signal route of an input signal in series. CONSTITUTION:When a signal 3phi is set to a high level signal and a signal 3phi is set to a low level signal, the low level signal 3phi is inputted to a gate and MP32 becomes a non-continuity state. Therefore, the third switch S3 is turned ON and the potential of the back gate of MP3 being PMOS is connected to the signal potential V1 of a signal route through MP31 brought to a continuity state. Therefore, even when the above mentioned signal potential V1 becomes almost equal to the min. signal in a circuit, no substrate bias effect is generated and it can be prevented that the ON-resistance of the MP3 being PMOS is largely varied by an input signal.
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