| 摘要 |
<p>PROBLEM TO BE SOLVED: To eliminate the influence of an offset voltage in the amplification circuit of a responder by fetching an offset voltage in advance before fetching data each time. SOLUTION: For example, when a command orders data to be read from a sensor circuit 16, a control circuit 11 turns off a switch circuit before fetching data from the sensor circuit 16 and fetches an output signal from an amplification circuit. At this time, only the offset voltage of an operational amplifier is amplified by the operational amplifier and fetched into the control circuit 11. The control circuit 11 stores the amplified offset voltage into a first storage circuit 2a as calibration data and inputs it into an amplification circuit. The signal of the sensor circuit 16 is amplified along with an offset voltage and fetched into the control circuit 11. The control circuit 11 stores the signal that has been fetched into a second storage circuit 12b. Then, data that are stored in the second storage circuit 12b are calibrated based on the calibration data being stored in the first storage circuit 12b and an offset voltage components is eliminated.</p> |
