A 1.8-V ΔΣ modulator interface for an electret microphone with on-chip reference

被引：30

作者：

Bajdechi, O ^{[1
]}

Huijsing, JH ^{[1
]}

机构：

[1] Delft Univ Technol, NL-2628 CD Delft, Netherlands

来源：

IEEE JOURNAL OF SOLID-STATE CIRCUITS | 2002年 / 37卷 / 03期

关键词：

analog-to-digital conversion; CMOS analog IC; continuous time; delta-sigma modulator; electret microphone; high input impedance; low-voltage bandgap reference; single-ended input; switched capacitor;

D O I：

10.1109/4.987078

中图分类号：

TM [电工技术]; TN [电子技术、通信技术];

学科分类号：

0808 ; 0809 ;

摘要：

The design of a delta-sigma (DeltaE) analog-to-digital converter (ADC) for direct voltage readout of an electret microphone is presented. The ADC is integrated on the same chip with a bandgap voltage reference and is designed to be packaged together with an electret microphone. Having a power consumption of 1.7 mW from a supply voltage of 1.8 V, the circuit is well suited for use in mobile applications. The single-loop, single-bit, fourth-order DeltaE ADC operates at 64 times oversampling for a signal bandwidth of 11 kHz. The measured dynamic range is 80 dB and the peak signal-to-(noise+ distortion) ratio is 62 dB. The harmonic, distortion is minimized by using an integrator with an instrumentation amplifier-like input which directly integrates the 125-mV peak single-ended voltage generated by the microphone. A combined continuous-time/switched-capacitor design is used to minimize power consumption.

引用

页码：279 / 285

页数：7

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BAUMHAUER JC, 1977, Patent No. 4046974

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