用于多气象传感器的模拟前端集成电路设计  

An Analog front-end IC for multiple meteorological sensors

作　　者：华文浩 张加宏[1,2] 蒋相龙 张波[2] 卢光林 Hua Wenhao;Zhang Jiahong;Jiang Xianglong;Zhang Bo;Lu Guanglin(Jiangsu Collaborative Innovation Center on Atmospheric Environment and Equipment Technology,Nanjing University of Information Science and Technology,Nanjing 210044,China;School of Integrated Circuits,Nanjing University of Information Science and Technology,Nanjing 210044,China)

机构地区：[1]南京信息工程大学江苏省大气环境与装备技术协同创新中心,南京210044 [2]南京信息工程大学集成电路学院,南京210044

出　　处：《电子测量技术》2024年第17期16-22,共7页Electronic Measurement Technology

基　　金：国家重点研发计划(2022YFB3205902,2022YFB3205903)项目资助。

摘　　要：设计了一款适用于多气象传感器的模拟前端集成电路,主要包含LDO、可编程增益放大器、SAR ADC以及湿度测量电路。可编程增益放大器采用全差分轨对轨运放作为主体结构来抑制噪声,同时采用连续时间Auto-Zero校准技术来降低其输入失调电压。对于14位SAR ADC,为降低DAC电容阵列的平均功耗和面积,设计了基于V_(CM)-based开关切换策略的分段式差分DAC电容阵列。最后基于湿度传感器电容值与矩形波频率之间关系的原理,设计了湿度测量电路,湿度测量电路频率误差为0.03%。该模拟前端电路基于华虹0.18μm CMOS工艺,并通过Cadence Spectre软件进行电路设计、版图绘制以及仿真验证。后仿真结果表明,电路整体可以实现从输入模拟信号的放大,到最终输出数字码的功能,其有效数(ENOB)为11.40 bit,SINAD为70.37 dB,SNR为71.05 dB,SFDR为83.85 dBc,THD为-78.55 dB。An analog front-end circuit for multi-meteorological sensors which mainly includes LDO,programmable gain amplifier,SAR ADC,and humidity measurement circuit was designed.The programmable gain amplifier uses all-difference rail to orbit as the main structure to suppress the noise,and the continuous-time Auto-Zero calibration technology is adopted to reduce its input imbalance voltage.For the 14-bit SAR ADC,in order to reduce the average power consumption and area of CDAC,a segmented differential DAC capacitor array based on the V_(CM)-based switching strategy was designed.Finally,based on the principle of the relationship between the capacitance value of the humidity sensor and the frequency of the rectangular wave,a humidity measurement circuit was designed.The frequency error of the humidity measurement circuit is 0.03%.The analog front-end circuit is based on Hua Hong′s 0.18μm CMOS process,and the circuit design,layout drawing and simulation verification are carried out through Cadence Spectre software.The post-simulation results show that the circuit as a whole can realize the function of amplifying the input analog signal and finally outputting the digital code,its effective number of bit(ENOB)is 11.40 bit,SINAD is 70.37 dB,SNR is 71.05 dB,SFDR is 83.85 dBc,and THD is-78.55 dB.

关 键 词：模拟前端 线性稳压器 可编程增益放大器 逐次逼近型模数转换器 湿度测量电路 

分 类 号：TN492[电子电信—微电子学与固体电子学]