Vibrating gyro

drv agcdrv agc btlagc agc drv drvA piezoelectric vibrator of a vibration gyro vibrates in response to a drive voltage Vinput into a drive electrode, and when deformed by a Coriolis force, generates detection voltages V, between which a potential difference corresponds to the deformation, at detection electrodes. An AGC circuit outputs a drive voltage Vwhile performing automatic gain control so that the detection voltages Vhave a given amplitude. A phase inversion circuit and a BTL amplifier circuit output a BTL voltage V, whose phase is opposite to the detection voltage Vand whose amplitude has been increased, to the detection electrodes via detection resistances. The AGC circuit reduces the detection voltages Vin order to prevent the drive voltage Vfrom exceeding a design upper limit value V′.