摘要
利用斩波稳定技术,设计了一种用在Σ-Δ调制器中的低噪声全差分开关电容积分器,电路中的运算放大器采用套筒式共源共栅结构.详细分析了开关电容积分器中存在的非理想特性,同时讨论了斩波稳定的原理,在此基础上对积分器中的运算放大器、开关和电容进行了具体设计.经Cadence环境下的Spectre仿真验证,在3.3V电源电压下,运算放大器的单位增益带宽为110MHz,开环直流电压增益达76dB,积分器在14kHz处的等效输入噪声电压为0.2μV·Hz-1/2.
A low noise fully differential switched-capacitor integrator used in the Σ-Δ modulator was designed by using the chopper stabilization technology. The telescopic cascode structure was adopted in the operational amplifier. Various nonidealities in the switched-capacitor integrator were analyzed in detail. The principle of chopper stabilization was also discussed. Finally,the detailed designs of the operational amplifier,switches and capacitors in the integrator were completed. The Spectre simulation under the Cadence environment indicates that,at a power supply of 3.3 V,the operational amplifier has a unity-gain bandwidth of 110 MHz,an open-loop gain of 76 dB,and the switched-capacitor integrator has an equivalent input noise voltage of 0.2 μV·Hz-1/2 at 14kHz.
出处
《微电子学与计算机》
CSCD
北大核心
2010年第5期153-156,共4页
Microelectronics & Computer
基金
科技部科技型中小企业技术创新基金(07C26223201317)
教育部新世纪优秀人才支持计划(NCET-06-0484)
江苏省自然科学基金(BK2007026)
