Title :
A new low-power sigma-delta modulator with the reduced number of op-amps for speech band applications
Author :
Safarian, Amin Qasem ; Sahandi, Farzad ; Atarodi, S. Mojtaba
Author_Institution :
Sharif Univ. of Technol., Tehran, Iran
Abstract :
An area and power-efficient second order sigma-delta modulator is presented. At system level, we propose a new single-loop single-stage modulator that uses only one class-AB op-amp to realize a second order noise shaping for speech band applications. The modulator shows 86 dB DR in 4 kHz speech bandwidth. It consumes 125 μW from a 2.5 V supply.
Keywords :
circuit feedback; circuit simulation; low-power electronics; network synthesis; operational amplifiers; sigma-delta modulation; speech processing; 125 muW; 2.5 V; 4 kHz; class-AB opamp; filter feedback loop; low-power sigma-delta modulator; opamp number reduction; power-efficient modulator; second order noise shaping; second order sigma-delta modulator; single-loop modulator; single-stage modulator; speech band processing; speech bandwidth; Capacitors; Delta-sigma modulation; Filters; Frequency; Noise reduction; Noise shaping; Operational amplifiers; Quantization; Signal to noise ratio; Speech;
Conference_Titel :
Circuits and Systems, 2003. ISCAS '03. Proceedings of the 2003 International Symposium on
Print_ISBN :
0-7803-7761-3
DOI :
10.1109/ISCAS.2003.1205743
