Patent ID: 6246287
Filing Date: 2001-06-12
Classification: G01P

Abstract:
An amplifier for a piezoelectric acceleration sensor for amplifying an output voltage from the piezoelectric acceleration sensor, comprising:an operational amplifier having a non-inverting input terminal that is connected to an output terminal of the acceleration sensor, an inverting input terminal and an output terminal;a leakage resistor connected between the non-inverting input terminal of said operational amplifier and a reference voltage;a first capacitor connected between the inverting input terminal of said operational amplifier and the reference voltage;a first resistor connected in series with said first capacitor;first and a second voltage dividing resistors connected in series with each other, between the output terminal of said operational amplifier and the reference voltage; anda second resistor and a second capacitor connected in parallel with each other between a connection point of the first and second voltage dividing resistors and the inverting input terminal of said operational amplifier,wherein, when a capacitance value of said first capacitor is C1, a resistance value of said first resistor is R2, a capacitance value of said second capacitor is C2, and a resistance value of said second resistor is R3, the expression C1.times.R2<C2.times.R3 is satisfied.