US 11,916,575 B2
Digital microphone assembly with improved mismatch shaping
Mohammad Sadegh Mohammadi, Lyngby (DK); and Mohammad Shajaan, Copenhagen (DK)
Assigned to KNOWLESELECTRONICS, LLC., Itasca, IL (US)
Filed by Knowles Electronics, LLC, Itasca, IL (US)
Filed on Dec. 31, 2020, as Appl. No. 17/139,743.
Prior Publication US 2022/0209789 A1, Jun. 30, 2022
Int. Cl. H03M 3/00 (2006.01); B81B 7/00 (2006.01); H04R 1/04 (2006.01); H04R 3/02 (2006.01); H04R 19/04 (2006.01)
CPC H03M 3/464 (2013.01) [B81B 7/008 (2013.01); H04R 1/04 (2013.01); H04R 3/02 (2013.01); H04R 19/04 (2013.01); B81B 2201/0257 (2013.01); B81B 2207/03 (2013.01); H04R 2201/003 (2013.01)] 21 Claims
OG exemplary drawing
 
1. A digital sensor assembly comprising:
a transducer configured to generate an electrical signal upon detecting an environmental condition;
a delta-sigma analog-to-digital converter (ADC) having an input coupled to the transducer and configured to output a digital signal based on the electrical signal, the ADC comprising a digital-to-analog converter (DAC) comprising a plurality of DAC elements in a feedback path of the ADC; and
a dynamic element matching (DELM) entity coupled between the output of the ADC and the DAC, the DELM entity configured to select a subset of DAC elements for each sample period using data weighted averaging (DWA) combined with a randomized shift of a selected subset of DAC elements from one sample period to the next,
wherein the selected subset of DAC elements contribute to an analog feedback signal that is combined with the electrical signal prior to input to the ADC during each sample period.