The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 22, 2020
Filed:
Oct. 11, 2019
Cirrus Logic International Semiconductor Ltd., Edinburgh, GB;
Paul Wilson, Edinburgh, GB;
Cirrus Logic, Inc., Austin, TX (US);
Abstract
This application relates to amplifier circuitry for amplifying an input signal from a MEMS capacitive sensor. The amplifier circuitry includes a first amplifier for receiving the input signal (V) and outputting a first output signal (V) based on the input signal. A second amplifier is configured to output a second output signal (V) which varies inversely with the first output signal. The first and second amplifier outputs are connected via first and second impedances so that a voltage at a common-mode node is equal to a common-mode voltage of the first and second output signals. The second amplifier has an input stage having an input terminal connected to a first reference voltage (V) and a feedback terminal connected to the common-mode node. The second amplifier also has an output stage connected between an output terminal of the input stage and the second amplifier output.