Title :
A dual-mode low-distortion sigma-delta modulator with relaxing comparator accuracy
Author :
Chio, Kin-Sang ; U, Seng-Pan ; Martins, R.P.
Author_Institution :
Analog & Mixed-Signal VLSI Lab., Macau Univ.
Abstract :
A dual-mode single-loop multibit (3 bits) sigma-delta modulator (SDM) with reduced number of op-amps is proposed for satisfying the GSM/WCDMA standard. Such architecture is based in a simplified analog structure that not only features low distortion but also provides an aggressive and significantly enlarged noise shaping bandwidth with low over-sampling ratio (OSR). In addition, the resolution of comparators in the quantizer is relaxed to reduce the power consumption. Simulations in system- and transistor-level simulations prove a dynamic range of 88dB & 60dB in GSM & WCDMA respectively
Keywords :
comparators (circuits); operational amplifiers; sigma-delta modulation; GSM standard; WCDMA standard; noise shaping bandwidth; operational amplifiers; over-sampling ratio; quantizer; relaxing comparator; sigma-delta modulator; Circuit simulation; Circuit topology; Communication standards; Delta-sigma modulation; Dynamic range; Energy consumption; GSM; Multiaccess communication; Noise shaping; Operational amplifiers;
Conference_Titel :
Circuits and Systems, 2006. ISCAS 2006. Proceedings. 2006 IEEE International Symposium on
Conference_Location :
Island of Kos
Print_ISBN :
0-7803-9389-9
DOI :
10.1109/ISCAS.2006.1692979
