用于高精度模数转换器的CMOS可变增益放大器  

A CMOS Variable Gain Amplifier for High-Precision Analog-to-Digital Converters

作　　者：李振国 苏萌 田迪 肖春 侯佳力 胡毅 沈红伟 王亚彬 Li Zhenguo;Su Meng;Tian Di;Xiao Chun;Hou Jiali;Hu Yi;Shen Hongwei;Wang Yabin(Bejing Smart-Chip Microelectronics Technology Co.,Ltd.,Bejing 100192,China;State Grid Shanxi Marheting Service Center,Taiyuan 030032,China)

机构地区：[1]北京智芯微电子科技有限公司,北京100192 [2]国网山西省电力公司营销服务中心,太原030032

出　　处：《半导体技术》2024年第10期899-905,共7页Semiconductor Technology

基　　金：国家电网有限公司总部管理科技项目(5700-202355614A-3-2-ZN)。

摘　　要：针对工业领域数据采集系统对大摆幅模拟信号精确采样的需求,提出了一种方便与高精度模数转换器(ADC)集成的CMOS可变增益放大器(VGA)。该VGA基于反相放大器结构,在5 V单电源供电的条件下支持最大±10 V信号输入。对传递函数的设计和电路结构的优化可保证VGA高线性度的同时不降低信噪比(SNR)。电路采用TSMC 0.18μm CMOS工艺进行设计并流片,面积为0.23 mm^(2),5 V供电时功耗为1.5 mW。在输入信号1 kHz、采样率200 kS/s条件下,将VGA与16 bit逐次逼近寄存器(SAR)ADC进行联合测试,测试结果表明信噪比达到89.80 dB,总谐波失真(THD)为-102.31 dB。该VGA具有输入范围大、精度高、面积小的特点,为工业信号采集应用提供了高集成度的解决方案。A CMOS variable gain amplifier(VGA)that is easy to integrate with high precision analog-to-digital converters(ADCs)was proposed to meet the accurate sampling need of large-swing analog signals for data acquisition systems in the industrial field.The VGA was based on an inverting amplifier structure and supported a maximum±10 V signal input under single power supply of 5 V.The design of transfer function and optimization of the circuit structure can ensure high linearity of the VGA without reducing the signal-to-noise ratio(SNR).The circuit was designed and fabricated in TSMC 0.18μm CMOS process with an area of 0.23 mm^(2)and a power consumption of 1.5 mV under 5 V power supply.The VGA was tested with a 16 bit successive approximation register(SAR)ADC under the condition of an input signal frequency of 1 kHz and a sampling rate of 200 kS/s.The test results indicate that the SNR achieves 89.80 dB,and the total harmonic distortion(THD)achieves-102.31 dB.The VGA has the characteristics of large input range,high accuracy and small area,providing a highly integrated solution for industrial applications.

关 键 词：可变增益放大器(VGA) CMOS工艺 宽摆幅 模数转换器(ADC) 低噪声 低失真 

分 类 号：TN722.77[电子电信—电路与系统] TN432