Study and analysis of coefficient mismatch in a MASH21 sigma—delta modulator

作     者：葛彬杰 王新安 张兴 冯晓星 汪清勤 

作者机构：Key Laboratory of Integrated Microsystem Science & Engineering ApplicationsShenzhen Graduate School of Peking University 

出 版 物：《Journal of Semiconductors》 (半导体学报（英文版）)

年 卷 期：2010年第31卷第1期

页      面：79-82页

核心收录：

学科分类：080902[工学-电路与系统] 0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 

基　　金：supported by the Shenzhen Science and Technology Plan China(No.QK200610) 

主　　题：mismatch leakage modeling sigma-delta modeling DC gain 

摘      要：The quantization noise leakage of the first stage in a MASH21 sigma-delta modulator is analyzed. The results show that the finite DC gain of the opamp is the main reason for noise leakage, and finite GBW and SR only generate harmonic distortion. The relationship between DC gain and leakage is modeled and conclusions on design criteria are reached. As an example, a MASH21 modulator for a digital audio application is realized. This modulator, fabricated in an 0.18 μm mixed signal process, achieves an SNDR of 91 dB with 1.8 V supply, which verifies the analysis and design criteria.