【作者】 张磊；

【导师】 吴金； 刘桂芝；

【作者基本信息】 东南大学 ， 集成电路工程（专业学位）， 2022， 硕士

【摘要】 光电检测技术是利用光电传感器实现微弱信号测量并成像的新兴技术,因紫外光在自然界中具有背景噪声小、抗干扰能力强和选择性好等特点,紫外光检测技术在军事、航天、工业和医学等方面已获得广泛的应用。随着材料技术和第三代半导体探测器的发展,紫外光电探测(Ultraviolet photoelectric detection)技术获得巨大进步,并对读出电路(Readout Integrated Circuit,ROIC)提出了更高的性能需求,高集成度、宽动态范围(Wide dynamic range)和高线性度是紫外读出电路的重要发展方向。本文基于第三代紫外半导体探测器设计了一款高线性度、宽动态范围的微弱电流信号读出电路。通过自动增益切换(Gain switching)的方式,将10p A～1m A的光电流信号平均分为四个档位进行分段响应处理。基于电容反馈跨阻放大器(Capacitive Transimpedance Amplifier,CTIA)的积分电路可为探测器提供稳定偏压,并具有高注入效率、低非线性的优点。在积分电容固定的条件下,时序控制电路通过调节积分时间改变其跨阻增益,完成前三档电流的积分放大。当进入档位四的大电流检测时,采用低增益的缓冲栅调制电路处理。通过上述方法,控制增益与感应电流相匹配,实现了微弱光电流的分档位精确检测,提高了测量动态范围和输出的线性度。最后通过先积分后读出(Integrate Then Readout,ITR)的方式,利用双通道的相关双采样(Correlated Double Sampling,CDS)电路将检测电压采样并输出,有效减小了复位噪声和KTC噪声,提高了信噪比。基于TSMC 0.18μm标准CMOS工艺,完成了2×2阵列系统电路及版图设计与后仿真验证。读出电路的整体版图面积为370×800μm~2,芯片测试结果表明,在5V的电源电压和25℃的条件下,线性输出摆幅为3V,CTIA满阱容量为3.72Me-,四档增益模式的总动态范围达到了140d B,实现了对100p A～1m A光电流的精确放大和采样输出,各个增益模式下的平均线性度超过了98%,最低线性度为97.21%,阵列电路实际功耗为54.8m W。更多还原

【Abstract】 Photoelectric detection technology is a new technology that uses photoelectric sensors to measure and image weak signals.Due to the characteristics of low background noise,strong anti-interference ability and good selectivity in nature,ultraviolet detection technology has been widely used in military,aerospace,industry and medicine.With the development of material technology and the third generation semiconductor detectors,ultraviolet photoelectric detection technology has made great progress,and put forward higher performance requirements for readout integrated circuit(ROIC).High integration,wide dynamic range and high linearity are the important development directions of ultraviolet readout circuit.Based on the third generation UV semiconductor detector,a high linearity and wide dynamic range weak current signal readout circuit is designed in this paper.By means of automatic gain switching,the photocurrent signal of 10p A～1m A is divided into four gears for segmented response processing.The integrating circuit based on capacitive transimpedance amplifier(CTIA)can provide a stable bias voltage for the detector,and has the advantages of high injection efficiency and low nonlinearity.Under the condition that the integrating capacitor is fixed,the timing control circuit changes its cross resistance gain by adjusting the integrating time to complete the integration amplification of the first three gears of current.When the high current detection of gear 4 is entered,the low gain buffer gate modulation circuit is used.Through the above method,the control gain is matched with the induced current,and the precise detection of the weak photocurrent is realized,and the dynamic range and output linearity are improved.Finally,by integrating then reading(ITR),the detection voltage is sampled and output by using the correlated double sampling(CDS)circuit of two channels,which effectively reduces the reset noise and KTC noise and improves the signal-to-noise ratio.Based on TSMC 0.18μm standard CMOS process,2×2 array system circuit and layout design and post simulation verification.The overall layout area of the readout circuit is 370×800μm~2.The chip test results show that under the conditions of 5V power supply voltage and 25℃,the linear output swing is 3V,the full well capacity of CTIA is 3.72Me-,the total dynamic range of the four gain modes reaches 140d B,and the accurate amplification and sampling output of 100p A～1m A photocurrent are realized.The average linearity under each gain mode exceeds 98%,and the minimum linearity is 97.21%,The actual power consumption of the array circuit is 54.8mw.更多还原