US 11,889,252 B2
Method and apparatus for balancing detection sensitivity in producing a differential signal
Mark Niederberger, Einsiedeln (CH); Thomas Gautschi, Zürich (CH); Michael Kuntzman, Chicago, IL (US); Mohsin Nawaz, Lombard, IL (US); Mohammad Shajaan, Copenhagen (DK); and Christian Lillelund, Fredensborg (DK)
Assigned to Knowles Electronics, LLC, Itasca, IL (US)
Filed by Knowles Electronics, LLC, Itasca, IL (US)
Filed on May 11, 2021, as Appl. No. 17/317,832.
Prior Publication US 2022/0369013 A1, Nov. 17, 2022
Int. Cl. H04R 1/08 (2006.01); H03F 3/183 (2006.01); H04R 29/00 (2006.01); H04R 1/04 (2006.01); H04R 19/04 (2006.01); H04R 3/00 (2006.01); H04R 1/26 (2006.01); B81B 7/00 (2006.01)
CPC H04R 1/083 (2013.01) [H03F 3/183 (2013.01); H04R 1/04 (2013.01); H04R 1/265 (2013.01); H04R 3/00 (2013.01); H04R 19/04 (2013.01); H04R 29/004 (2013.01); B81B 7/0006 (2013.01); B81B 2201/0257 (2013.01); H03F 2200/03 (2013.01); H03F 2200/09 (2013.01); H04R 2201/003 (2013.01)] 23 Claims
OG exemplary drawing
 
1. A microphone device comprising:
a sensor having a pair of transduction elements organized and arranged for respectively producing first and second electrical signals, which are substantially 180 degrees out of phase and which are each associated with a respective one of a pair of output terminals, where each one of the pair of transduction elements has a potential difference in sensitivity to a detected stimulus, which can manifest in the first and second electrical signals that are being respectively produced by the pair of transduction elements of the sensor, that have a difference in amplitude; and
an interface circuit including:
a bias voltage generator having one or more bias output voltage terminals, where a respective one of one or more DC bias voltages is produced at each of the bias output voltage terminals, which are coupled to the pair of transduction elements of the sensor;
an amplifier circuit having a first input terminal coupled to a first one of the pair of output terminals of the sensor and having a second input terminal coupled to a second one of the pair of output terminals of the sensor, the amplifier circuit producing at a pair of output terminals a differential output signal; and
a compensation circuit coupled to the amplifier circuit for producing a balance signal based on an output signal being produced by the amplifier circuit, wherein the balance signal compensates for any difference in amplitude in the first and second electrical signals that are received by the amplifier circuit from the sensor.