一种集成IIR滤波的三阶噪声整形逐次逼近ADC设计  

A third-order noise shaping SAR ADC with integrated IIR filter

作　　者：佟星元 孙鼎宇 辛昕 TONG Xingyuan;SUN Dingyu;XIN Xin(School of Electronic Engineering,Xi’an University of Posts and Telecommunications,Xi’an,710121,China;Shaanxi Provincial Research Center for Telecommunication ASIC Design,Xi’an,710121,China)

机构地区：[1]西安邮电大学电子工程学院,陕西西安710121 [2]陕西省通信专用集成电路设计工程技术研究中心,陕西西安710121

出　　处：《西安邮电大学学报》2024年第4期57-66,共10页Journal of Xi’an University of Posts and Telecommunications

基　　金：国家自然科学基金项目(62104193,62271389)。

摘　　要：针对经典噪声整形(Noise-Shaping,NS)无源逐次逼近型(Successive Approximation Register,SAR)模数转换器(Analog-to-Digital Converter,ADC)精度较低问题,提出了一种动态放大器与无限冲激响应(Infinite Impulse Response,IIR)滤波器级联的三阶NS-SAR ADC设计方法。利用动态放大器增益和IIR滤波器积分来补偿余量电压损失,以提高NS-SAR ADC的精度。同时,采用基于浮动反相器的放大器(Floating Inverter Amplifier,FIA)提高ADC的稳健性。基于0.18μm互补金属-氧化物-半导体(Complementary Metal Oxide Semiconductor,CMOS)工艺进行设计,实验结果表明,设计的ADC在考虑工艺-电压-温度波动的情况下,以10 bits电路结构实现了大于4.3 bits的有效位数提升;在1.8 V电源电压、2 kS/s采样速率和8倍过采样率条件下,信噪失真比为88.2 dB,功耗为1.05μW,能效优值为168.9 dB。与经典NS-SAR ADC设计相比,所提设计实现了较高的ADC精度。To address the issue of low precision in classical noise-shaping(NS)successive approximation register(SAR)analog-to-digital converters(ADCs),a third-order NS-SAR ADC design method combining a dynamic amplifier and an infinite impulse response(IIR)filter is proposed.The precision of the NS-SAR ADC is improved by compensating for the loss of residual voltage through dynamic amplifier gain and IIR filter integral.Meanwhile,the robustness is enhanced by using a floating inverter amplifier(FIA).The ADC is designed in a 0.18μm CMOS technology,achieving an effective numbers of bits(ENOB)greater than 4.3 bits at a 10 bits circuit structure while considering process-voltage-temperature variations;At a power supply of 1.8 V,a oversampling rate(OSR)of 8 and a sampling rate of 2 kS/s,the signal-to-noise-distortion ratio is 88.2 dB and the power consumption is 1.05μW,resulting in a Schreier figure-of-merit(FoMs)of 168.9 dB.Compared with the classical NS-SAR ADC design,the proposed design achieves higher ADC precision.

关 键 词：模数转换器 噪声整形 动态放大器 无限冲激响应滤波器 余量电压 

分 类 号：TN431.1[电子电信—微电子学与固体电子学]