A microphone readout interface with 74-dB SNDR

A continuous-time (CT) sigma-delta modulator (SDM) for condenser microphone readout interfaces is presented in this paper. The CT SDM can accommodate a single-ended input and has high input impedance, so that it can be directly driven by a single-ended condenser microphone. A current-sensing boosted...

Full description

Saved in:
Bibliographic Details
Published inAnalog integrated circuits and signal processing Vol. 81; no. 1; pp. 241 - 252
Main Authors Du, Dingkun, Odame, Kofi
Format Journal Article
LanguageEnglish
Published Boston Springer US 01.10.2014
Subjects
Circuits and Systems
Electrical Engineering
Engineering
Signal,Image and Speech Processing
OTA-C integrators
Feedforward compensation
Continuous-time sigma-delta modulators
Microphone readout
Single-ended to differential conversion
Online AccessGet full text

Cover

More Information
Summary:A continuous-time (CT) sigma-delta modulator (SDM) for condenser microphone readout interfaces is presented in this paper. The CT SDM can accommodate a single-ended input and has high input impedance, so that it can be directly driven by a single-ended condenser microphone. A current-sensing boosted OTA-C integrator with capacitive feedforward compensation is employed in the CT SDM to achieve high input impedance and high linearity with low power consumption. Fabricated in a 0.35 - μ m complementary metal-oxide-semiconductor (CMOS) process, a circuit prototype of the CT SDM achieves a peak signal-to-noise-and-distortion ratio of 74.2 dB, with 10-kHz bandwidth and 801 - μ W power consumption.
ISSN:0925-1030
1573-1979
DOI:10.1007/s10470-014-0383-0