| 摘要 |
PROBLEM TO BE SOLVED: To fully reduce the error of the detection value of physical quantity being obtained finally when improving the detection accuracy of the physical quantity by utilizing the same operational amplifier for amplifying a detection signal that indicates physical quantity to be detected and for amplifying a temperature signal for compensating the temperature of the detection signal. SOLUTION: A reference signal Sa from a reference voltage generation circuit 5, a temperature signal St from a bridge circuit 4 for detecting temperature, and a detection signal Sd from a bridge circuit 3 for detecting pressure are processed by time sharing through an analog multiplexer 6, and the signals Sd, St, and Sa are sampled through an identical differential amplification circuit 8 and an A/D conversion circuit 9 with operational amplifiers 8a and 8b. A correction operation circuit 14 calculates a pressure quantity detection value according to the detection signal Sd while temperature is compensated for by an operation processing based on digital data from the A/D conversion circuit 9 and a correction coefficient from an EPROM 13. Trimming resistors Rw1-Rw4 are provided to adjust the potential level of the detection signal Sd and the temperature signal St to a state being identical to the potential level of the reference signal Sa.
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