| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a small-sized physical quantity sensor capable of detecting accurately physical quantities in a plurality of ranges from one physical quantity transducer. <P>SOLUTION: The acceleration transducer 1 outputs an electric signal in response to an acting acceleration to the first amplifier 20 formed on a semiconductor circuit chip 2. The first amplifier amplifies an acceleration signal at the first amplification degree to be output to an MPX 22 and the second amplifier 21 for amplifying it at the second amplification degree. The MPX switches outputs from the first and second amplifiers in every switching period to be output to an ADC 23, so as to be brought therein into a time-serial digital signal comprising two signals, and outputs it to an outside of the circuit chip via a communication circuit 26. The AD-converted output from the second amplifier is negative-fed back to the second amplifier via a digital HPF 24 and a DAC 25. A high-level acceleration signal and a low-level signal from which a drift component of a low frequency is removed are obtained at the same time by this manner. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
