標題: On reducing leakage quantization noise of multistage Sigma Delta modulator using nonlinear oscillation
作者: Chang, TH
Dung, LR
Guo, JY
電控工程研究所
Institute of Electrical and Control Engineering
公開日期: 2005
摘要: This paper presents an improved architecture of the multistage (MASH) multibit sigma-delta modulators (Sigma Delta Ms). The architecture can be immune to circuit nonidealities over a large portion of input range when oversampling ratio (OSR) is low, and hence the dynamic range (DR) can be improved. Our approach is based on two resonator topologies, high-Q cascade-of-resonator-with-feedforward (HQCRFF) and low-Q cascade-of-integrator-with-feedforward (LQCIFF). The key to improving DR is to use HQCRFF-based single-bit structure in the first stage and have the first stage oscillated. When the first stage oscillates, the coarse quantization noise vanishes and hence circuit nonidealities, such as finite op-amp gain and capacitor mismatching, do not cause leakage quantization noise problem. In addition, because of the in-band zeros introduced by the resonators, the proposed architecture enhances the suppression of the in-band quantization noise for wideband applications. As the results of simulation, the proposed MASH architecture can inherently have wide DR without using additional calibration techniques.
URI: http://hdl.handle.net/11536/17769
ISBN: 0-7803-8834-8
ISSN: 0271-4302
期刊: 2005 IEEE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS (ISCAS), VOLS 1-6, CONFERENCE PROCEEDINGS
起始頁: 2555
結束頁: 2558
顯示於類別:會議論文