公开(公告)号：US12126366B2

公开(公告)日：2024-10-22

申请号：US17950486

申请日：2022-09-22

Applicant: NXP B.V.

Inventor： Dave Sebastiaan Kroekenstoel ,  Muhammad Kamran ,  Harry Neuteboom ,  Costantino Ligouras ,  Sergio Andrés Rueda Gómez

IPC: H03M3/00 ,  H04R3/00 ,  H03M1/12

CPC classification number: H03M3/484 ,  H03M3/392 ,  H04R3/00 ,  H03M1/12 ,  H03M3/354

Abstract: Embodiments of multi-mode sigma-delta analog-to-digital converter (ADC) circuits and a microphone circuit are disclosed. In an embodiment, a multi-mode sigma-delta ADC circuit includes a pair of operational transconductance amplifiers (OTAs), a filter connected to the pair of OTAs, a quantizer connected to the filter, a differential digital-to-analog converter (DAC) connected to the quantizer, and a controller configured to switch the multi-mode sigma-delta ADC circuit between a single-ended operational mode, a pseudo differential operational mode, and a full differential operational mode to improve common mode rejection (CMR) performance by controlling the pair of OTAs. An output of a microphone and a differential output of the differential DAC are inputted into input terminals of the pair of OTAs.

公开(公告)号：US12095483B2

公开(公告)日：2024-09-17

申请号：US17950582

申请日：2022-09-22

Applicant: NXP B.V.

Inventor： Dave Sebastiaan Kroekenstoel ,  Muhammad Kamran ,  Harry Neuteboom ,  Costantino Ligouras ,  Sergio Andrés Rueda Gómez

IPC: H03M3/00 ,  H04R3/00

CPC classification number: H03M3/484 ,  H03M3/354 ,  H04R3/00

Abstract: Embodiments of sigma-delta analog-to-digital converter (ADC) circuits and a microphone circuit are disclosed. In an embodiment, a sigma-delta ADC circuit includes a pair of operational transconductance amplifiers (OTAs), a filter connected to the pair of OTAs, a quantizer connected to the filter, a differential digital-to-analog converter (DAC) connected to the quantizer, and a bias compensation circuit configured to measure a biasing condition of a first OTA of the pair of OTAs and to apply the biasing condition of the first OTA to a second OTA of the pair of OTAs to reduce Total Harmonic Distortion Plus Noise (THD+N) in the sigma-delta ADC circuit. An output of a microphone and a differential output of the differential DAC are inputted into input terminals of the pair of OTAs.