| 摘要 |
PROBLEM TO BE SOLVED: To enable a voltage higher than conventional voltage to be applied to a vibrator, making it possible to increase the vibration amplitude of the vibrator.SOLUTION: A capacitance detection circuit 7 is configured so as to include: a C-V conversion circuit 8 composed of a full differential amplifier 11 and feedback capacitors Cf1, Cf2; an input common mode feedback circuit 9, having a reference voltage input terminal 14, for controlling an average voltage of the inverted input terminal and non-inverting input terminal of the full differential amplifier 11 to a voltage to be inputted to the reference voltage input terminal 14; and a reference voltage generation circuit 10 for outputting a reference voltage signal varying at a higher frequency than a resonance frequency of a vibrator 4, to the reference voltage input terminal 14. It is thereby made possible to apply a high voltage to the vibrator 4, and hence to increase a vibration amplitude of the vibrator. |
