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US 12,601,774 B2Granted
Low noise readout interface for capacitive sensors with negative capacitance
AssigneeInvenSense, Inc.
InventorsStefano Valle, Tomasz E. Hanzlik
Life of this patent
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Abstract
Disclosed embodiments provide a self-contained topology that enables a significant noise reduction of capacitive sensor readout interfaces. For example, various embodiments can provide low noise capacitive sensor readout interfaces or analog front ends having a main buffer amplifier in a bootstrap configuration, wherein a bootstrap loop configuration comprises a negative capacitance coupled to an input of the main buffer amplifier with a negative impedance converter.
Claims20
An apparatus, comprising:
- a source follower sensor readout interface comprising a main buffer amplifier, wherein the main buffer amplifier is configured in a bootstrap configuration at an output of a capacitive sensor;
- and
- a bootstrap loop of the bootstrap configuration comprising a negative capacitance coupled to an input of the main buffer amplifier, wherein the bootstrap configuration comprising the negative capacitance coupled to the input of the main buffer amplifier is configured to reduce noise associated with the source follower sensor readout interface and that is attributable to the main buffer amplifier.
A method, comprising:
- applying a negative capacitance at an input of a main buffer amplifier in a source follower sensor readout interface associated with a capacitive sensor, wherein the main buffer amplifier is configured in a bootstrap configuration at an output of the capacitive sensor;
- reducing source follower sensor readout interface noise via a bootstrap loop of the bootstrap configuration, wherein the bootstrap loop of the bootstrap configuration coupled to the negative capacitance is configured to reduce noise associated with the source follower sensor readout interface and that is attributable to the main buffer amplifier.
Dependencies are inferred from the claim text.