US 11,743,666 B2
Microphone assembly with transducer sensitivity drift compensation and electrical circuit therefor
Vezio Malandruccolo, Rapperswil (CH); Mark Niederberger, Einsiedeln (CH); Luca Bettini, Zurich (CH); and Weiwen Dai, Elgin, IL (US)
Assigned to KNOWLES ELECTRONICS, LLC., Itasca, IL (US)
Filed by Knowles Electronics, LLC, Itasca, IL (US)
Filed on Dec. 30, 2020, as Appl. No. 17/138,487.
Prior Publication US 2022/0210591 A1, Jun. 30, 2022
Int. Cl. H04R 29/00 (2006.01); H04R 3/00 (2006.01); H04R 1/04 (2006.01); B81B 7/00 (2006.01); H04R 19/04 (2006.01)
CPC H04R 29/004 (2013.01) [B81B 7/008 (2013.01); H04R 1/04 (2013.01); H04R 3/00 (2013.01); H04R 19/04 (2013.01); B81B 2201/0257 (2013.01); B81B 2207/03 (2013.01); H04R 2201/003 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A sensor assembly comprising:
a housing having an external-device interface;
a capacitive transducer disposed in the housing and configured to generate an electrical signal;
a bias control circuit comprising an environmental sensor configured to generate an environmental sensor signal based on change in an environmental condition affecting drift in sensitivity of the transducer; and
an integrated circuit disposed in the housing and electrically coupled to contacts of the external-device interface, the integrated circuit comprising:
a transducer bias circuit coupled to the transducer and to the bias control circuit, the transducer bias circuit configured to adjust the bias applied to the transducer based on the environmental sensor signal;
wherein adjustment of the bias compensates for drift in sensitivity of the transducer caused by the change in the environmental condition.