| 摘要 |
PURPOSE: To miniaturize a sensor device by providing measures against high-frequency noise without providing a feedthrough capacitor in the case of the sensor device. CONSTITUTION: A filter circuit is constituted by utilizing existing resistors 17, 19, and 22 directly connected to a power line V and connecting capacitors 35-37 to the resistors in a constant-current circuit 200 and an amplification circuit 300 of a semiconductor pressure sensor. Further, a power line V' which is different from the power line V is provided for a power supply to operational amplifiers 29-32, and a filter circuit is formed at the power line V' by a resistor 40 and a capacitor 39. Further, a filter circuit is formed for the output of the operational amplifier 32 by a resistor 25 and a capacitor 38. The filter circuits provide measures against a high-frequency noise. |
