Abstract: A resonance circuit is configured to receive a pulse density signal obtained by ??-modulating an analog displacement signal by a ?? modulator and a multi-bit signal obtained from the pulse density signal and to generate an excitation signal based on the pulse density signal and the multi-bit signal. The resonance circuit includes an amplification factor controller configured to set an amplification factor depending on a vibration signal obtained from the multi-bit signal, a multiplier configured to amplify a level of the pulse density signal by the amplification factor, and a circuit group configured to generate the excitation signal based on a pulse density signal obtained by further ??-modulating an output of the multiplier. The amplification factor controller is configured to set the amplification factor using a proportional control and an integral control based a difference between an amplitude signal obtained from the vibration signal and a target amplitude value.

Abstract: A resonance circuit is configured to receive a pulse density signal obtained by ??-modulating an analog displacement signal by a ?? modulator and a multi-bit signal obtained from the pulse density signal and to generate an excitation signal based on the pulse density signal and the multi-bit signal. The resonance circuit includes an amplification factor controller configured to set an amplification factor depending on a vibration signal obtained from the multi-bit signal, a multiplier configured to amplify a level of the pulse density signal by the amplification factor, and a circuit group configured to generate the excitation signal based on a pulse density signal obtained by further ??-modulating an output of the multiplier. The amplification factor controller is configured to set the amplification factor using a proportional control and an integral control based a difference between an amplitude signal obtained from the vibration signal and a target amplitude value.