A Fully Integrated CMOS Readout Circuit for Particle Detectors

Novel schemes for a charge sensitive amplifier （CSA） and a CR-（RC）, semi-Gaussian shaper in a fully integrated CMOS readout circuit for particle detectors are presented. The CSA is designed with poly-resistors as feedback components to reduce noise. Compared with conventional CSA, the input referred equivalent noise charge（ENC） is simulated to be reduced from 5036e to 2381e with a large detector capacitance of 150pF at the cost of 0.5V output swing loss. The CR-（RC）,semi-Gaussian shaper uses MOS transistors in the triode region in series with poly-resistors to compensate process variation without much linearity reduction.

Design of Diode Type Un-Cooled Infrared Focal Plane Array Readout Circuit

The diode infrared focal plane array uses the silicon diodes as a sensitive device for infrared signal measurement. By the infrared radiation, the infrared focal plane can produces small voltage signals. For the traditional readout circuit structures are designed to process current signals, they cannot be applied to it. In this paper, a new readout circuit for the diode un-cooled infrared focal plane array is developed. The principle of detector array signal readout and small signal amplification is given in detail. The readout circuit is designed and simulated by using the Central Semiconductor Manufacturing Corporation （CSMC） 0.5 μm complementary metal-oxide-semiconductor transistor （CMOS） technology library. Cadence Spectre simulation results show that the scheme can be applied to the CMOS readout integrated circuit （ROIC） with a larger array, such as 320×240 size array.

Design and implementation of GM- APD array readout circuit for infrared imaging

Based on an avalanche photodiode（ APD） detecting array working in Geiger mode（ GM-APD）, a high-performance infrared sensor readout integrated circuit（ ROIC） used for infrared 3D（ three-dimensional） imaging is proposed. The system mainly consists of three functional modules, including active quenching circuit（ AQC）, time-to-digital converter（ TDC） circuit and other timing controller circuit. Each AQC and TDC circuit together constitutes the pixel circuit. Under the cooperation with other modules, the current signal generated by the GM-APD sensor is detected by the AQC, and the photon time-of-flight（ TOF） is measured and converted to a digital signal output to achieve a better noise suppression and a higher detection sensitivity by the TDC. The ROIC circuit is fabricated by the CSMC 0. 5 μm standard CMOS technology. The array size is 8 × 8, and the center distance of two adjacent cells is 100μm. The measurement results of the chip showthat the performance of the circuit is good, and the chip can achieve 1 ns time resolution with a 250 MHz reference clock, and the circuit can be used in the array structure of the infrared detection system or focal plane array（ FPA）.

Readout circuit with nonuniformity correction for the uncooled microbolometer

The output of uncooled microbolometer is nonuniform, and the traditional two-point nonuniformity correction method requires a tight restriction on substrate temperature. The circuit proposed by this article can relax the restriction on the substrate temperature and perform nonuniformity correction when reading out the image signal. The dummy pixels reduce static current. And the Column shared DACs transfer correction data to the gates of MOS transistors and the positive reference edge of amplifier, to control the bias current of detector and dummy one, and set the start point of integration. This circuit has higher sensitivity, wider dynamic range, and frame frequency of more than 30 Hz for 128×128 array. PSPICE simulation results seem that this circuit functions well.

Low Noise Readout Circuit for Biosensor SoC

Presented is a low noise interface circuit that is tuned to the needs of self-assembly monolayers biosensor SoC. The correlated double sampling(CDS) unit of the readout circuit can reduce 1/f noise, KTC noise and fixed noise of micro arrays effectively. The circuit is simulated in a 0.6 μm/level 7 standard CMOS process, and the simulated results show the output voltage has a good linearity with the transducing current of the micro arrays. This is a novel circuit including four amplifiers sharing a common half-circuit and the noise reducing CDS unit. It could be widely used for micro array biosensors.

A 97 dB dynamic range CSA-based readout circuit with analog temperature compensation for MEMS capacitive sensors

Abstract： This paper presents a charge-sensitive-amplifier （CSA） based readout circuit for capacitive microelectro-mechanical-system （MEMS） sensors. A continuous-time （CT） readout structure using the chopper technique is adopted to cancel the low frequency noise and improve the resolution of the readout circuits. An operational trans-conductance amplifier （OTA） structure with an auxiliary common-mode-feedback-OTA is proposed in the fully differential CSA to suppress the chopper modulation induced disturbance at the OTA input terminal. An analog temperature compensation method is proposed, which adjusts the chopper signal amplitude with temperature variation to compensate the temperature drift of the CSA readout sensitivity. The chip is designed and implemented in a 0.35μm CMOS process and is 2.1 × 2.1 mm2 in area. The measurement shows that the readout circuit achieves 0.9 aF/√H capacitive resolution, 97 dB dynamic range in 100 Hz signal bandwidth, and 0.8 mV/fF sensitivity with a temperature drift of 35 ppm/℃ after optimized compensation.

Particle detector readout integrated circuit of 0.18μm technology with 164 e equivalent noise charge

Integrated circuits of deep submicron(DSM) CMOS technology are advantageous in volume density, power consumption and thermal noise for multichannel particle detection systems,but there are challenges in the front-end circuit design.In this paper,we present a 0.18μm CMOS front-end readout circuit for low noise CdZnTe detectors in tens of pF capacitance.Solutions to the noise and gate leak problems in DSM technologies are discussed in detail.A prototype chip was designed,with a charge sensitive preamplifier,a 4th order semi-Gaussian shaper and several output drivers.Test results show that the chip has an equivalent noise charge of 164 e,without connecting it to a detector,with an integral nonlinearity of<0.21%and differential nonlinearity of<3.75%.

Design and test results of a low-noise readout integrated circuit for high-energy particle detectors

A low-noise readout integrated circuit for high-energy particle detector is presented.The noise of charge sensitive amplifier was suppressed by using single-side amplifier and resistors as source degeneration.Continuous-time semi-Gaussian filter is chosen to avoid switch noise.The peaking time of pulse shaper and the gain can be programmed to satisfy multi-application.The readout integrated circuit has been designed and fabricated using a 0.35 μm double-poly triple-metal CMOS technology.Test results show the functions of the readout integrated circuit are correct.The equivalent noise charge with no detector connected is 500–700 e in the typical mode,the gain is tunable within 13–130 mV/fC and the peaking time varies from 0.7 to 1.6 μs,in which the average gain is about 20.5 mV/fC,and the linearity reaches 99.2%.

New CMOS readout circuit with background suppression and CDS for infrared focal plane array applications

A high injection, large dynamic range, stable detector bias, small area and low power consumption CMOS readout circuit with background current suppression and correlated double sampling (CDS) for a high-resolution infrared focal plane array applications is proposed. The detector bias error in this structure is less than 0.1 mV. The input resistance is ideally zero, which is important to obtain high injection efficiency. Unit-cell occupies 10 μm × 15 μm area and consumes less than 0.4 mW power. Charge storag...

高速数字化三维集成式CCD-CMOS图像传感器

为了解决CCD与CMOS工艺兼容性低、互连集成制作难度大,以及芯片间接口匹配和高性能兼备等问题,对CCD器件拓扑结构与像元、CMOS读出电路、三维异质互连集成及高密度引脚封装等技术进行研究,提出了一种1024×256阵列规模的集成式CCD-CMOS图像传感器。该器件实现了CCD信号的高精度数字化处理、高速输出及多芯粒的技术融合,填补了国内CCDCMOS三维集成技术空白。测试结果表明:集成CCD-CMOS器件的光响应和成像功能正常,双边成像效果良好,图像无黑条和坏列,互连连通率(99.9%)满足三维集成要求,实现了集成式探测器件的大满阱高灵敏度成像(满阱电子数达165.28ke^(-)、峰值量子效率达86.1%)、高精度数字化(12bit)和高速输出(行频率达100.85kHz),满足集成化、数字化、小型化的多光谱探测成像系统要求。

基于磁性传感器的低失调温度补偿接口电路设计

面向磁性传感器在物联网(IoT)技术中的广泛应用,该文基于180 nm CMOS工艺设计了一种具有低失调电压,低温度漂移特性的霍尔传感器接口电路。针对霍尔传感器灵敏度的温度漂移特性,该文设计了一种感温电路并与查表法相结合,调节可编程增益放大器(PGA)的增益有效地降低了霍尔传感器的温度系数(TC)。在此基础上,通过在信号主通路中使用相关双采样(CDS)技术,极大程度上消除了霍尔传感器的失调电压。仿真结果表明,在–40°C~125°C温度范围内,霍尔传感器的TC从966.4 ppm/°C减小到了58.1 ppm/°C。信号主通路的流片结果表明,霍尔传感器的失调电压从25 mV左右减小到了4 mV左右,霍尔传感器的非线性误差为0.50%。芯片的总面积为0.69 mm^(2)。

一种集成图像处理功能的数字像元焦平面读出电路

设计了一种像元级数字化焦平面读出电路,克服了传统模拟读出电路技术的电荷容量局限,实现了更大的动态范围和更低噪声的数字化图像读出;同时在像元内部进行数字化图像处理,可实现非均匀校正(NUC)、盲元补偿、数字时间延迟积分(TDI)、空间滤波等图像预处理功能。该电路采用40 nm CMOS工艺流片,面阵规格为640×512,像元步进为30μm,全芯片尺寸约22 mm×19 mm。测试结果显示,该电路通过TDI、空间滤波功能可大幅降低(分别约90%和63%)输出图像空间噪声,提升成像质量。

基于带隙基准的改进型像元共享CTIA红外读出电路设计

为了提高红外读出电路动态范围、增强红外成像质量,加入暗电流抑制模块电路,设计了一种四像元分时共享的电容反馈跨阻放大器(CTIA)和带隙基准源相互配合的高性能红外读出电路。通过带隙基准源产生两个基准电压586 mV和293 mV,其中293 mV基准电压值的温漂系数达到1.49×10-6/℃,可对分流管的栅极和源极提供稳定的电压偏置,实现对暗电流的精准撇除。结果表明,该电路可实现电流信号从10 pA~10 nA宽动态范围的积分电压读出,读出数据通过线性拟合,拟合优度R 2达到0.9992,说明电路性能良好。此研究未来可应用到线列和面阵的红外探测器中。

消除CDS折叠效应的增益自适应红外焦平面读出电路

高动态范围是红外焦平面探测技术的先进发展方向之一。高集成度像元读出电路的动态范围受到小电荷存储容量和噪声的限制。所设计的增益自适应像元读出电路,小信号下为电容反馈跨阻放大器(CTIA),大信号下自动转换为变阻抗电阻反馈跨阻放大器(RTIA),实现小信号大增益、大信号小增益的自动切换,将集成3.86 fF积分电容的CTIA电荷容量拓展到1.63 Me^(–)。在15μm像元中心距的像元内集成相关双采样(CDS)结构,大幅减小噪声。对CDS大信号注入产生的折叠效应进行理论分析,并设计抗折叠结构。采用180 nm 3.3V CMOS工艺,完成640×512规模的读出电路的设计、仿真、流片、测试。测试结果显示,该电路可消除CDS折叠效应,噪声电子数17 e^(–),动态范围拓展到99.66 dB。

激光3维成像线性焦平面探测器读出电路研究进展

激光焦平面探测器是一种新型的光电成像器件,它利用半导体内部载流子的雪崩倍增效应实现高速、高灵敏度、纳秒级时间分辨探测,用于凝视型激光3维成像系统。探测器主要分为线性和盖革两大类,其中线性模式探测器具有响应速度快、无死时间和后脉冲、可实现单脉冲瞬时成像等优点。首先介绍了在不同应用场景下,线性模式焦平面读出电路的两种架构并简述其原理,然后阐述像素单元的关键电路模块,比较了其优缺点,最后分析了两种减小行走误差的双阈值时刻鉴别方法。为相关领域的研究者提供了一些有益的参考和借鉴。

高光谱应用的带可调复位时间CDS的低噪声红外焦平面读出电路

低辐射量的高光谱应用对红外焦平面读出电路(ROIC)提出了低噪声的设计要求。相关双采样(CDS)是常用的减少噪声的结构。本文通过调节钳位和采样保持之间的时间间隔来改进CDS,可灵活消除低频噪声。采用180 nm CMOS工艺设计和制造了640×512规模、15μm像元中心距的读出电路。输入级集成了低噪声CTIA与本文提出的可调复位时间CDS(AICDS),所设计的时序产生器使CDS复位时间可以延长0~270个时钟周期。通过延长复位时间减少这个时间间隔,噪声电子数可以由39 e^(-)减少到18.3 e^(-)。SPECTRE仿真结果和实验测试结果证实了提出的AICDS结构可以提升高光谱应用读出电路的噪声性能,因此可以广泛应用。

太赫兹光热电探测器读出方法

太赫兹光热电探测器基于热生载流子在温度梯度驱使下迁移的原理实现太赫兹波探测,具有快响应、超宽带、自供电、室温工作及结构简单等优势,受到广泛关注。目前,探测器读出主要采用调制-解调方法,通过电流放大器与锁相放大器级联实现测量,集成度低,成本高,难以实现阵列读出。为满足光谱测量、成像感知等应用需求,本文对光热电阵列探测器单元读出方法进行研究。从探测器机理出发,对输出信号进行建模分析;在此基础上设计板级专用读出电路,实现前置放大与锁相放大功能。测试表明,该方法可以在强噪声背景环境下对太赫兹光热电探测器进行高精确度读出,增益达到140.7 dB,信噪比改善了38.3 dB。

一种高帧频大动态范围像素级数字化读出电路设计

与短波和中波器件相比,长波红外探测器具有较大的光电流和暗电流,故需要强大的电荷存储能力。而使用传统的模拟像元读出电路技术会严重受限于电荷存储能力,使得长波探测器的动态范围和信噪比难以提升,从而制约着长波红外成像系统的发展和应用。提出一种像素级数字读出电路技术,通过数字积分克服了传统模拟积分方案电荷存储能力受限的缺陷,实现了探测器的数字信号输出,能够极大提高探测器的动态范围、抗干扰能力和帧频。该技术是提升长波探测器性能的有效途径。基于该技术设计了一款像元间距为30 m的320×256数字读出电路,其输出以低压差分信号(Low Voltage Differential Signal,LVDS)方式传输。仿真结果显示,该电路的最高帧频可达1000 Hz,动态范围大于95 dB。

一种具有积分电容复用功能的红外读出电路设计

为提高长波红外探测器的电荷处理能力,提出了一种积分电容复用技术。该技术将读出电路阵列分为奇偶行两个部分,使奇偶行像素分开进行积分读出。当所有的奇行像素积分时,所有的偶行像素均不进行积分。奇行像素复用偶行像素的积分电容,奇行像素积分结束后按行列顺序依次读出。同样地,当所有偶行像素积分时,奇行像素不进行积分,偶行像素复用奇行像素的电容,积分完成后偶行像素按顺序读出。相比于使用叠层电容来提高电荷处理能力的方法,积分电容复用技术更加有效且不受工艺限制。仿真结果表明,积分电容复用技术可将像素的等效积分电容提升至原来的2倍,使读出电路的电荷处理能力从20 Me^(-)提升至40 Me^(-)。

一款多色叠层量子阱红外探测器的读出电路设计

一款完整的红外焦平面探测器主要包含探测器件、读出电路、封装结构和制冷组件。目前根据不同应用场景,探测波段范围不断变宽、探测灵敏度需求提高、成像速度要求加快,对探测器设计提出了更严格、更复杂的指标要求。其中,读出电路将探测光信号转换为电信号传输至系统,是探测器组件的关键核心模块。本文设计了一款对应多色叠层量子阱型器件的红外焦平面探测器读出电路,能够实现同时间、同空间对四波段信号进行探测,并且同时读出,四波段信号的探测积分与读出之间没有互相干扰。探测器规格640×512,像元间距50μm(四波段),各波段信号可实现分时积分、分别可调,采用边积分边读出工作模式,读出帧频可达到四波段探测时≥50 Hz,电路噪声≤0.5 mV,动态范围≥70 dB,电功耗≤600 mW,是一款超大规模低噪声高帧频的高性能读出电路。