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:
Sep. 30, 2025
Filed:
Dec. 12, 2023
Panasonic Intellectual Property Management Co., Ltd., Osaka, JP;
Makoto Takemoto, Kanagawa, JP;
Susumu Yoneta, Kanagawa, JP;
Panasonic Automotive Systems Co., Ltd., Kanagawa, JP;
Abstract
A microphone module includes: a microphone element outputting a microphone signal representing collected sound; an amplifier circuit outputting an amplified signal obtained by amplifying a difference between the microphone signal and a reference voltage; a high-pass filter outputting a high-band amplified signal obtained by filtering the amplified signal; a buffer circuit outputting an audio signal obtained by buffering the high-band amplified signal; a first low-pass filter outputting a low-pass bias voltage obtained by filtering the audio signal superimposed on a DC power supply, and a separation circuit outputting an internal bias voltage obtained by removing the influence of an external circuit from the low-pass bias voltage. The second low-pass filter outputs the reference voltage obtained by filtering the internal bias voltage. A circuit from the high-pass filter to the amplifier circuit is set such that an open loop gain is smaller than 0 dB.