Title :
A low-power continuous-time ΔΣ modulator for Electret microphone applications
Author :
Zare-Hoseini, Hashem ; Kale, Izzet ; Richard, C S Morling
Author_Institution :
Cambridge Silicon Radio (CSR), Cambridge, UK
Abstract :
A continuous-time delta-sigma modulator that maybe used as an interface for Electret microphones is presented. The third order modulator comprises a single-ended-to-differential-converter integrated inside the loop-filter with a single-ended high-impedance input, an RC integrator on the first stage and Gm-C integrators for the other stages. Gm-C integrators comprise highly-linear low-power transconductances. The modulator has been designed and fabricated in the TSMC 0.18um technology for audio application (300Hz-10kHz) with a single supply voltage of 1.8V and a single-ended input signal with a peak of 125mV. The measured dynamic range of the modulator is 86dB with a power consumption of 240uA.
Keywords :
continuous time filters; delta-sigma modulation; electrets; impedance convertors; integrating circuits; low-power electronics; microphones; Gm-C integrator; RC integrator; audio application; current 240 muA; electret microphone application; frequency 300 Hz to 10 kHz; gain 86 dB; loop-filter; low-power continuous-time ΔΣ modulator; low-power transconductance; power consumption; single-ended high-impedance input; single-ended-to-differential-converter; size 0.18 mum; third order modulator; voltage 1.8 V; voltage 125 mV; Electrets; Impedance; Linearity; Microphones; Modulation; Transconductance; Transistors;
Conference_Titel :
Solid State Circuits Conference (A-SSCC), 2010 IEEE Asian
Conference_Location :
Beijing
Print_ISBN :
978-1-4244-8300-6
DOI :
10.1109/ASSCC.2010.5716630
