Resonator circuit having reduced effects of parasitic feed-through capacitance
AssigneeThe Regents of the University of California
InventorKenneth E. Wojciechowski
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Abstract
Parasitic feed-through capacitance effects in a resonator circuit are reduced by separating the resonator signal from the feed-through capacitance signal and then detecting the resonator signal with comparator circuitry. In specific embodiments, the separation of the resonator signal from the feed-through capacitance signal is effected by serial integrator and differentiator circuitry or by trans-impedance amplifier circuitry. The comparator circuitry can include control/delay circuitry for enabling the comparator at a correct time when feed-through capacitance signal has dissipated. The invention can be implemented using microelectromechanical sensors (MEMS) in a strain gauge function.
Claims13
A resonator circuit comprising:
- a resonator body having an input and an output,
- an integrator connected to the resonator output for integrating an output signal at the output,
- a differentiator connected to receive an integrated output from the integrator,
- a comparator connected to the differentiator for determining when an output voltage from the differentiator reaches a predetermined voltage, and
- a feedback loop from the comparator to the resonator input for applying a square wave comparator output voltage to the resonator.
A resonator circuit comprising:
- a resonator body having an input and an output,
- a trans-impedance amplifier operably connected to the resonator output for amplifying an output signal,
- comparator circuitry operably connected to receive a sense voltage from the trans-impedance amplifier and provide a square wave output signal, and
- a feedback loop for applying the square wave output signal to the input of the resonator body.
Dependencies are inferred from the claim text.