Single-chip A/D converter for digital microphones with on-chip preamplifier and time-domain noise isolation
A 1-bit sigma-delta modulator (ΣΔΜ) with an on-chip preamplifier for digital electret microphones has been implemented. A differential gm-opamp-RC preamplifier eliminates the traditional single-ended JFET interface and is integrated with an on-chip ΣΔΜ by removing all external components. The propos...
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Published in | Electronics letters Vol. 45; no. 3; p. 1 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Stevenage
John Wiley & Sons, Inc
29.01.2009
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Subjects | |
Online Access | Get full text |
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Summary: | A 1-bit sigma-delta modulator (ΣΔΜ) with an on-chip preamplifier for digital electret microphones has been implemented. A differential gm-opamp-RC preamplifier eliminates the traditional single-ended JFET interface and is integrated with an on-chip ΣΔΜ by removing all external components. The proposed time-domain noise isolation technique preserves circuit performance under a single power supply condition. The prototype implemented in a 0.18 μm CMOS technology achieves a 78 dB dynamic range and 62 dB peak signal-to-noise + distortion ratio (both A-weighted) with a current consumption of 450 μΑ under a 1.8 V supply. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0013-5194 1350-911X |