非线性直流增益对Delta-Sigmal开关电容调制器的影响  

Modeling of Switched-Capacitor Delta-Sigmal Moulators in Simulink

作　　者：潘宇[1] 吴玉广[1] 吴琨[1] 

机构地区：[1]西安电子科技大学微电子学院,陕西西安710071

出　　处：《微电子学与计算机》2008年第4期63-67,71,共6页Microelectronics & Computer

摘　　要：现有的Delta-Sigmal开关电容调制器模型中,没有考虑积分器的有限直流增益(DCG)非线性因素.通过对非线性DCG分析、估算,给出它的分析、估算与模型.同时给出一套精确的开关电容Δ∑调制器的行为级模型.该模型同时考虑了噪声(开关与运放的热噪声)、时钟抖动,以及非理想情况下,积分器与运放的有限直流增益与单位增益带宽等因素.通过对二阶调制器行为级模型的仿真,验证了非线性有限直流增益会使调制器的输出谐波失真、背景噪声急剧增加,加剧了调制器在行为级上的不可预测性.The DCG nonlinearity of the integrators, which is not considered in many △∑ modulators＇ modeling attempts, is analyze, estimated, and modeled by the paper. Precise behavioral modeling of switched-capacitor modulators is presented, considering noise（switches and op-amps thermal noise）, clock jitter, nonidealities of integrators and op-arnps including finite dc-gain（DCG） and unity gain band width et. it is shown that neglexting this parameter would lead to a significant undererstimation of the modulators＇ behavior and increase the noise floor as well as the harmonic distortion at the output of the modulator.

关 键 词：时钟馈通 Delta—Signal调制器 开关电容 有限直流增益 

分 类 号：TN4[电子电信—微电子学与固体电子学]