| 摘要 |
PURPOSE:To always obtain the amplified output of an input by providing MOS transistors respectively between two operational amplifiers and a common output terminal, and between the common output terminal and the output terminal of the first operational amplifier, and besides, between the common terminal and the output terminal of a second operational amplifier. CONSTITUTION:A transistor switch 10 is connected between a terminal 14 to output an inverted signal for a positive phase input and a positive phase input terminal 13, and a capacity for offset compensation is connected between a grounding voltage and the terminal 13, and the transistor switch 11 is connected between the negative phase input terminal and the grounding voltage. When phi1 is low, the switches 10, 11 turn on, and at this time, if the terminal 14 is considered to be a standard, the positive phase input terminal of the operational amplifier 8 turns to the negative phase input terminal, and the negative phase input terminal turns to the positive phase input terminal. Therefore, it comes to be a voltage follower, and the voltage of the terminal 13 comes to be the offset voltage Vos of the positive phase input terminal when the negative phase input terminal of the operational amplifier 8 is considered to be the standard. When phi1 is high, the switches 10, 11 turn off and it the positive phase input terminal is considered to be the standard, the negative phase input terminal comes exactly to be a virtual grounding voltage, and the offset voltage is compensated.
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