Title :
A 0.9mW microphone uplink system in 65nm CMOS
Author :
Mohieldin, Ahmed N. ; Mekky, Rania H. ; Emira, Ahmed ; Omar, Mohammed ; Elwan, Hassan
Author_Institution :
Design Center, Newport Media Inc., Cairo, Egypt
Abstract :
The implementation of a complete low-power microphone uplink system is presented. The system comprises a low-dropout regulator (LDO), an input operational transconductance amplifier (OTA), and a 3rd order continuous-time sigma-delta (SigmaDelta) modulator. The LDO provides biasing to the microphone and OTA input. The OTA presents high input impedance to the microphone and act as a pre-amplifier. The OTA consumes 100 muA from 3.3 V supply and SigmaDelta modulator consumes 480 muA from 1.2 V supply at a sampling frequency of 3 MHz and achieves dynamic range of 81.5d B. A decimation filter is added after the SigmaDelta modulator with decimation factor 64. The design has been implemented in 65 nm CMOS process and occupies 0.25 mm2.
Keywords :
CMOS integrated circuits; microphones; network synthesis; operational amplifiers; preamplifiers; sigma-delta modulation; OTA; and A CMOS process; continuous-time sigma-delta modulator; current 100 muA; current 480 muA; decimation filter; frequency 3 MHz; low-dropout regulator; low-power microphone uplink system; operational transconductance amplifier; power 0.9 mW; preamplifier; size 65 nm; voltage 1.2 V; voltage 3.3 V; Delta-sigma modulation; Dynamic range; Filters; Frequency; Impedance; Microphones; Operational amplifiers; Regulators; Sampling methods; Transconductance;
Conference_Titel :
Circuits and Systems, 2009. ISCAS 2009. IEEE International Symposium on
Conference_Location :
Taipei
Print_ISBN :
978-1-4244-3827-3
Electronic_ISBN :
978-1-4244-3828-0
DOI :
10.1109/ISCAS.2009.5117964
