ANGULAR VELOCITY SENSOR

摘要

Disclosed is an angular velocity sensor provided with a sensor element, which has a vibrating body, a sense electrode, a drive electrode, and a monitor electrode. The monitor electrode generates signals corresponding to vibration of a vibrating body. A sense circuit outputs signals, which indicate an angular velocity applied to the vibrating body, based on the signals outputted from the sense electrode. An amplitude determining circuit measures the amplitude of the vibration of the vibrating body. A PLL circuit includes: a constant voltage outputting device which generates a constant voltage; a timing switching section, which performs switching between a voltage that corresponds to a monitor signal, and the constant voltage, and which selectively outputs the voltage; and a voltage-controlled oscillator which outputs oscillation signals having a frequency that corresponds to the voltage outputted from the timing switching section. When the amplitude measured by means of the amplitude determining circuit is a predetermined value or less, the timing switching section outputs the constant voltage that has been outputted from the constant voltage outputting device to the voltage-controlled oscillator, and outputs start-up mode signals. The angular velocity sensor has stable output characteristics.