| 摘要 |
PROBLEM TO BE SOLVED: To remove the offset-voltage of each operational amplifier using a simple circuit configuration, even when using the plurality of operational amplifiers in a method and a circuit for removing the offset voltage of the operational amplifier that is used especially for the differential amplification of an input voltage. SOLUTION: In the circuit configuration indicated in figure 1, a switch S1 is connected to a terminal F and a switch S2 is connected to a terminal H, first. Furthermore, input voltages V1 and V2 are turned to equal voltages (offset-voltage measuring period). Thereafter, the switch S1 is connected to a terminal G, and the switch S2 is disconnected from the terminal H. Thus, the offset voltages of the respective operational amplifiers A1-A3 are removed. Also, even if the plurality of operational amplifiers are used, since the need of an offset-voltage adjusting circuit for each operational amplifier is eliminated, the configuration will not become complex as the circuit as a whole. COPYRIGHT: (C)2007,JPO&INPIT
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