Inertial sensor

#The present invention relates to an inertial sensor, and relates to, for example, a technique effective in a case of application to an acceleration sensor that detects micro-vibrational acceleration.

#JP-A-2013-076610 (PTL 1) discloses a technique relevant to an acceleration sensor including a C/V conversion circuit having an increase or decrease in capacitance with respect to acceleration by applying sinusoidal signals having opposite phases to a pair of capacitive elements.

#JP-A-2014-102172 (PTL 2) discloses a technique relevant to an acceleration sensor including a C/V conversion circuit using a fully-differential operational amplifier (fully-differential operational amplifier). Specifically, an output signal from a pair of capacitive elements to which voltage signals having opposite phases are applied is input to the inverting input of the fully-differential operational amplifier, and an output signal from a pair of fixed capacitive elements having the same capacitance as that of the pair of capacitive elements mentioned above is input to the non-inverting input of the fully-differential operational amplifier.

#FIG. 1 is a schematic circuit diagram illustrating a configuration example of a CV conversion unit and a sensor unit of an acceleration sensor in an associated technique.

#FIG. 2 is a diagram illustrating a schematic circuit configuration of an acceleration sensor in Embodiment 1.

#FIG. 3 is a diagram illustrating a modification example of the circuit configuration shown in FIG. 2.

#In the following embodiments, the invention will be described by division into a plurality of sections or embodiments, as necessary, for convenience. However, these sections or embodiments are not irrelevant to each other unless explicitly otherwise stated, and one section or embodiment is in relation to a modification example, details, supplementary explanation, or the like of all or a portion of other sections or embodiments.

#In addition, in the following embodiments, when mention is made of the number of elements and the like (including the number of pieces, numerical values, amounts, ranges, and the like), the number of elements is not limited to a specific number except for a case where the number thereof is particularly specified, a case where the number thereof is apparently limited to the specific number in principle, and the like, and may be equal to or greater (or less) than the specific number.

#Further, in the following embodiments, it goes without saying that components thereof (including element steps as well) are not necessarily indispensable except for a case where the components are particularly specified, a case where the components are considered to be apparently indispensable in principle, and the like.