Angular speed sensor

Abstract

An angular velocity sensor includes a vibration body, first and second sensor electrodes generating an electric charge responsive to an angular velocity applied to the vibration body, first and D/A converters each outputting at least two levels of an electric charge, first and second integrator circuits integrating the electric charge generated by the first and second sensor electrodes and the electric charges output from the first and second D/A converters, respectively, a comparator unit comparing output signals from the first and second integrator circuits, first and second D/A switching units switching levels of the output signals from the first and second D/A converters according to a comparison result of the comparator unit, a first disconnection detecting switch connected between the first sensor electrode and the first integrator circuit, a first voltage source for injecting an electric charge into a point between the first sensor electrode and the first integrator circuit via the first disconnection detecting switch, a second disconnection detecting switch connected between the second sensor electrode and the second integrator circuit, and a second voltage source for injecting an electric charge into a point between the second sensor electrode and the second integrator circuit via the second disconnection detecting switch. This angular velocity sensor has a high reliability and performs stable operation even if ambient environment changes.