Title :
A 2.5-V, 14-bit MASH sigma-delta modulator for ADSL
Author :
Chiang, Jen-Shiun ; Chen, Hsin-Liang ; Chou, Pou-Chu
Author_Institution :
Dept. of Electr. Eng., Tamkang Univ., Tamsui, Taiwan
Abstract :
This work presents a fourth order, multi-stage noise shaped (MASH) sigma-delta modulator (SDM) for wide bandwidth applications. Each stage of the SDM consists of a second order SDM with multi-level quantizer. The first stage is a low distortion second order single loop SDM, while the second stage of the SDM is a low distortion SDM with Chebyshev type II filter technique. The proposed architecture can reduce the signal distortion of circuits to improve the performance. A test SDM chip for ADSL application is designed and implemented by TSMC 0.25μm process. The simulation results indicate that the dynamic range (DR) could reach 87dB with power dissipation of 65mW.
Keywords :
Chebyshev filters; digital subscriber lines; modulators; quantisation (signal); sigma-delta modulation; transfer functions; 65 mW; ADSL; Chebyshev filter; MASH sigma-delta modulator; folded-cascode opamp; fully differential approach; low distortion second order single loop; multi-stage noise shaped modulator; multilevel quantizer; second order modulator; signal distortion; signal transfer function; wide bandwidth applications; Bandwidth; Chebyshev approximation; Circuit simulation; Circuit testing; Delta-sigma modulation; Distortion; Dynamic range; Filters; Multi-stage noise shaping; Power dissipation;
Conference_Titel :
Advanced System Integrated Circuits 2004. Proceedings of 2004 IEEE Asia-Pacific Conference on
Print_ISBN :
0-7803-8637-X
DOI :
10.1109/APASIC.2004.1349394
