应用于宽带Δ-∑ ADC的多级运算放大器  

Multi-Stage Operational Amplifier for Broadband Δ-∑ ADC

作　　者：徐肯[1] 蔡敏[1] 贺小勇[1] 

机构地区：[1]华南理工大学电子与信息学院,广东广州510640

出　　处：《华南理工大学学报（自然科学版）》2017年第1期42-47,共6页Journal of South China University of Technology(Natural Science Edition)

基　　金：国家科技重大专项(2010ZX03001-004-03)~~

摘　　要：为提高运算放大器的带内增益和带宽,提出了一款应用于长期演进(LTE)接收机中宽带Δ-∑模数转换器(ADC)的四级运算放大器.该运算放大器采用前馈Gm-C和密勒补偿相结合的混合型频率补偿方法,以保证运算放大器的稳定性.文中采用0.13μm1P6M CMOS工艺设计了一款高性能的四级运算放大器,并将该运算放大器应用于宽带Δ-∑ADC中.测试结果显示:该运算放大器在1.5 V供电电压下可获得72.8 d B的直流增益、442 MHz的增益带宽积和101 V/μs的转换率;在相同的功耗和带宽下,该放大器的带内(0~10 MHz)增益比传统的两级放大器提高了6 d B以上;采用该运算放大器的宽带Δ-∑ADC在10 MHz的信号带宽下具有68 d B的信噪比和78 d B的无杂散动态范围.In order to improve the in-band gain and bandwidth of operational amplifiers, a four-stage operational amplifier of the broadband Δ-∑ ADC used in long-term evolution receivers is proposed. In the operational amplifier, a hybrid frequency compensation scheme combining feedforward Gm-C and Miller technique is adopted to ensure the stability. Then, a high-performance four-stage operational amplifier is designed in 0.13 μm 1P6M CMOS technolo-gy, and it is applied to the broadband Δ-∑ ADC. Test results show that （1） with a power supply of 1.5 V, the ope-rational amplifier achieves a unity gain bandwidth of 442MHz, a DC gain of 72.8dB and a slew rate of 101 V/μs;（2） with the same bandwidth and power dissipation, the in-band （0 ？10 MHz） gain of the proposed amplifier is6dB more than that of the traditional two-stage operational amplifier; and （3） in a signal bandwidth of 10MHz, the broadband Δ-∑ ADC adopting the proposed amplifier achieves a SNR of 68 dB and a SFDR of 78 dB.

关 键 词：运算放大器 多级 频率补偿 宽带放大器 Δ-∑调制 模数转换器 

分 类 号：TN47[电子电信—微电子学与固体电子学]