Upconverting Capacitance-to-Voltage Converter for Readout of a Micromechanical Gyroscope

An upconverting front-end is implemented for readout of a bulk micromachined capacitive gyroscope. Detailed analysis of the integrated front-end, including the charge sensitive amplifier, high pass filters with gain and coherent amplitude detection is presented. Feasibility of the topology is compared to another realization of a continuous time front-end operating at the resonance frequency of the gyroscope. The spectral noise density of the implemented front-end is measured to be 0.11 aF/Hz
^1/2
, when reduced to input capacitance. Functionality of a complete gyroscope is demonstrated with the reported front-end performing the capacitive readout