Patent ID: 9046366
Filing Date: 2015-06-02
Classification: G01C

Abstract:
1. A signal processing circuit that causes a vibrator to oscillate, and generates a signal that corresponds to a magnitude of a predetermined physical quantity based on a detection signal of the vibrator, the signal processing circuit comprising: a current/voltage conversion section that converts an oscillation current of the vibrator into a voltage; a phase shift section that shifts a phase of a first signal that has been converted into a voltage by the current/voltage conversion section; a drive amplitude control section that converts the first signal that has been shifted in phase by the phase shift section into a switch control signal that is a binary signal, full-wave rectifies the first signal that has been shifted in phase by the phase shift section based on the switch control signal, and controls an amplitude of a drive signal that drives the vibrator based on the first signal that has been full-wave rectified; a reference signal generation section that generates a reference signal for synchronous detection based on the first signal that has been converted into a voltage by the current/voltage conversion section; a clock signal generation section that generates a clock signal having a frequency twice a frequency of the drive signal based on a phase difference between the reference signal and the switch control signal; a synchronous detection section that synchronously detects a second signal that includes the detection signal of the vibrator based on the reference signal; and a switched capacitor filter that filters the second signal that has been synchronously detected by the synchronous detection section based on the clock signal.