Patent ID: 6513383
Filing Date: 2003-02-04
Classification: B60R,G01P

Abstract:
An acceleration sensor comprising:a piezo-electric element for detecting an acceleration; an amplifier circuit for inputting voltage outputs of both ends of said piezo-electric element, and for giving a differential amplification signal, which is obtained by differentially amplifying the voltage outputs of both ends of said piezo-electric element, as a sensor output, said amplifier circuit having a first non-inverting amplifier circuit for non-inversion amplifying one voltage of said piezo-electric element, a second non-inverting amplifier circuit for non-inversion amplifying the other voltage of said piezo-electric element, and a differential amplifier circuit for differentially amplifying outputs of said first and second non-inverting amplifier circuits; a bias resistor circuit provided at an input side of said amplifier circuit; a capacitor inserted in parallel with said piezo-electric element in order to lower a lower cut-off frequency without increasing resistance values of said bias resistor circuit; a single temperature compensation element for adjusting gains of the first and second non-inverting amplifier circuits of said amplifier circuit so that an output-temperature characteristic of said piezo-electric element is compensated; and a reference voltage circuit for giving a reference potential to said amplifier circuit and said bias resistor circuit.