ACCELERATION SENSOR CIRCUIT AND TRI-AXIAL ACCELERATION SENSOR CIRCUIT

PROBLEM TO BE SOLVED: To provide an acceleration sensor circuit that has a wide dynamic range and high sensitivity and is efficient as well as inexpensive. SOLUTION: The acceleration sensor circuit includes: a first capacitor where capacitance changes according to detected acceleration; a second capacitor where capacitance varies in a direction contrary to that of the first capacitor by acceleration; a first amplifier where an amplification degree to an AC signal is determined according to the ratio of the capacity of the first capacitor to that of the second capacitor; and a second amplifier for generating a differential signal between an input AC signal input to the first amplifier and an amplification AC signal amplified by the first amplifier. COPYRIGHT: (C)2010,JPO&INPIT