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AssigneeCypress Semiconductor Corporation
InventorsSaravanan V. Murugesan, Paul Walsh, Gerard Baldwin, Kaveh Hosseini
Estimating the term…
Embodiments of a capacitance sensing system including an integrating amplifier and methods for operating the same to provide a higher slew rate and bandwidth are described. In one embodiment, the integrating amplifier comprises an input stage including an inverting input coupled to an electrode of a capacitor to sense a capacitance and a non-inverting input coupled to a reference potential, and an output stage including a compensating capacitor coupled to an output. The compensating capacitor comprises two smaller capacitors coupled in parallel and a switching element configured to open when the integrating amplifier is operated in a RESET mode decoupling one of the two smaller capacitors from the output to decrease capacitance of the compensating capacitor.
An integrating amplifier comprising:
The integrating amplifier of claim 3, wherein the integrating amplifier comprises parallel diode connected devices, and wherein one of the parallel diode connected devices is switched into an output stage current path when the integrating amplifier is operated in RESET mode to provide greater stability.
A capacitance sensing system comprising:
The capacitance sensing system 10, wherein the two smaller capacitors of the compensating capacitor comprise capacitances selected so that the capacitance of the compensating capacitor is decreased by about 50% when the integrating amplifier is operated in RESET mode.
A method for sensing capacitance of a capacitor, comprising:
Dependencies are inferred from the claim text.