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. 11, 2018
Filed:
Jul. 11, 2016
Knowles Electronics, Llc, Itasca, IL (US);
John J. Albers, Chicago, IL (US);
Thomas Froehlich, Premstaetten, AT;
Knowles Electronics, LLC, Itasca, IL (US);
AMS AG, Premstaetten, AT;
Abstract
A microphone assembly includes a capacitive MEMS transducer and a bias circuit having a DC output coupled to the transducer. The microphone assembly also includes a differential amplifier having a first input coupled to a first output of the transducer, the differential amplifier having a second input coupled to a second output of the transducer. The microphone assembly further includes a first impedance matching network and a second impedance matching network configured to balance a first capacitive load at the first input of the amplifier and a second capacitive load at the second input of the amplifier. Electrical signals applied by the transducer to the first and second inputs of the amplifier are matched or approximately matched in magnitude and 180 degrees or approximately 180 degrees out of phase with respect to each other.