基于FPGA的光谱仪动态基线补偿系统设计  

Design of FPGA-based spectrometer dynamic baseline compensation system

作　　者：于呈豪 薛萌 石朗杰 郭汉明[1] Yu Chenghao;Xue Meng;Shi Langjie;Guo Hanming(School of Optical-Electrical and Computer Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]上海理工大学光电信息与计算机工程学院,上海200093

出　　处：《电子技术应用》2024年第6期96-100,共5页Application of Electronic Technique

基　　金：上海市地方能力建设项目(21010502900)。

摘　　要：线阵型CMOS光电图像传感器具有灵敏度高、光谱响应范围大、功耗低、体积小等优点,被广泛应用于便携式光谱仪的开发中。为解决由CMOS图像传感器暗电流变大而造成的光谱仪基线漂移问题,设计一种基于FPGA的光谱仪动态基线补偿系统。系统利用传感器预留像素计算得到该帧图像的基线值并进行实时反馈,使用高性能运算放大器、差分放大器设计电压跟随电路、基线补偿电路和单端转差分电路对CMOS模拟信号进行处理并进行高速A/D转换,选用精密DAC芯片实时动态反馈基线补偿值。最终测试结果表明,随着积分时间的不断增加,该设计始终能使光谱数据保持一个较低的基线水平。系统电路设计灵活、光谱采集准确、基线控制效果良好,比较适合检测微弱光谱信号。The linear array CMOS photodetector sensor possesses advantages such as high sensitivity,a wide spectral response range,low power consumption,and a compact size.It is widely used in the development of portable spectrometers.To address the issue of baseline drift caused by the increasing dark current of the CMOS image sensor,a dynamic baseline compensation system based on FPGA for the spectrometer is designed.The system utilizes reserved pixels on the sensor to calculate the baseline value for each frame in real-time and provide feedback.It employs high-performance operational amplifiers,differential amplifiers for voltage tracking,baseline compensation circuits,and single-ended to differential circuits to process the CMOS analog signals and perform high-speed A/D conversion.A precision DAC chip is used to provide real-time dynamic feedback for baseline compensation values.The final test results demonstrate that as the integration time increases,this design consistently maintains a lower baseline level for spectral data.The system's circuit design is flexible,it ensures accurate spectral data acquisition,and it effectively controls the baseline,making it well-suited for detecting weak spectral signals.

关 键 词：光谱采集 线阵型CMOS FPGA 基线补偿 信号处理 

分 类 号：TN29[电子电信—物理电子学] TP23[自动化与计算机技术—检测技术与自动化装置]