半导体激光器驱动器的SPICE仿真及其在气体传感系统的应用

为了提高激光器的工作可靠性和稳定性,借助TINA-SPICE软件对其驱动电路进行辅助设计,并通过电调制和光电检测系统实验检验设计效果。对驱动器的恒流输出电路的幅频特性和瞬态响应进行仿真,预测潜在的电流振荡现象,并提出一种用于补偿环路增益的易用方案。通过对比补偿前后的仿真曲线,验证了该方案的可行性。在此基础上,以STM32H743作为中央处理核心,通过触摸屏图形化设置和监测驱动电流参数,从而调度激光器驱动电路的运行。在296 K环境温度下,利用该电路进行半导体激光器电调制特性实验,通过拟合波长与电流得到调制系数为0.045 cm-1/mA。进一步地,将该控制器引入基于红外光谱吸收技术的气体传感系统,完成了对甲烷气体的定量分析。分析结果表明,所设计的电路能稳定地驱动激光器并实现对波长的精准调制,获得的气体传感系统的检测下限低于8 ppm。

一种无桥高增益单级LED驱动电路及其混合控制策略

中小功率的LED驱动电源中,传统两级LED驱动电源存在体积大、成本高以及传统Boost PFC电路在低压输入时导通损耗大等问题。为此提出一种由无桥二次型Boost PFC电路和DC-DC LLC电路集成的无桥高增益单级LED驱动电路,实现了高电压增益、功率开关器件软开关、一套控制电路和高电路转换效率。针对单级电路在电网输入电压变化引起直流母线电压变动范围大等问题,设计一种适用于所提电路的APWM-PFM混合控制策略,并对混合控制原理和控制过程进行详细分析。最后设计一台200 W的实验样机,在输入电压80~120 Vrms范围内,占空比最大为0.5,最大电压增益为6.7,直流母线电压基于网侧特性和LLC电路特性设计在700 V以内,样机的功率因数值均高于0.990,THD均低于15%。在满载条件下,110 Vrms输入时,样机效率为93.20%,相比于传统无桥PFC,电压增益提高了2.21倍,实现了高电压增益和软开关,有效提升了在低压输入条件下的电路转换效率。仿真和实验结果验证了所提出电路和控制方法的有效性。

全国产化微弱信号调理电路

为更好地处理微弱信号,提出一种新型的多通道信号前端调理模块。该模块不仅具有可编程增益功能,而且还整合了带通滤波器。在保证高输入阻抗和低噪声等关键性能的同时,提出一种全面而创新的调理模块设计方案。该方案的核心是采用可编程增益放大电路,显著提高了模块在放大各类微弱信号时的适应性。此外,利用HC595系列芯片,实现了对增益的精确调控。该放大电路具备26 dB的固定增益和0~84 dB的可调增益范围,工作带宽设定在380~420 kHz。经过系统性能测试,结果表明该调理电路成功满足了设计目标的各项要求。

自适应增益光电探测电路设计

在激光模拟实兵对抗系统中,为解决传统光电探测电路受环境影响大,系统不稳定、检测效能低的问题,设计了一种基于单片机的增益自适应光电探测电路。在传统光电探测电路的基础上改用两个对称分布的跨阻放大反馈电路,消除光电探测器偏置分量,抑制前置放大电路的系统噪声;采用自动增益控制电路使不同射击距离下输出信号幅值保持稳定;采用多级滤波的方式去除信号的直流分量并有效抑制背景噪声,为信号的进一步处理提供准备。通过实验验证与TINA-TI仿真分析结果表明,该光电探测电路可以实现增益自适应变化,在不同入射距离下输出电压幅值基本稳定在2V左右。其性能明显优于传统固定增益电路,极大地提高了对光电信号的探测能力,该结果验证了本文提出的光电探测电路设计的科学性和可行性。

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。

基于三绕组耦合电感的准Z源高增益DC-DC变换器

针对清洁能源并网发电系统中直流升压变换器的现有技术缺陷,提出一种新型的准Z源高升压DC-DC变换器。该变换器通过将准Z源网络与独特的耦合电感集成结构结合,能在较低的占空比和匝比下实现高电压增益。拓扑中的钳位回路回收了储存在耦合电感漏感中的能量,能有效缓解耦合电感漏感引起的尖峰电压。此外,变换器功率器件电压应力水平较低,便于使用低耐压器件来提高转换效率。输入电流连续以及输入输出共地的特点使得该变换器适合应用于可再生能源场景。详细介绍了所提变换器的工作原理,给出了关键性的公式推导和设计依据,并进行性能比较。最后,设计并搭建一台200 W额定功率的样机进行实验验证,实验结果与理论分析相吻合。

Rail-to-rail op-amp with constant transconductance,SR and gain

A novel general-purpose low-voltage rail-to-rail CMOS （ complementary metal-oxide-semiconductor transistor ） operational amplifier （op-amp）is introduced, which obtains constant transconductance, slew rate and constant high gain over the entire input common mode voltage range. The proposed scheme has the potential for applications in deep submicrometer technology, as the operation of the circuit does not exclusively rely on the square-law or the linear-law of transistors. The scheme is compact and suitable for applications as VLSI cell. The rail-to- rail op-amp has been implemented in DPDM 0. 6 μm mixedsignal process. The simulations show that in the entire range of input common mode voltage, the variations in transconductance, SR and gain are 1%, 2. 3%, 1.36 dB, respectively. Based on this, the layout and tape-out are carded out. The area of layout is 0. 072 mm^2. The test results are basically consistent with the circuit simulation.

基于斩波稳定技术的可编程增益放大器

为满足模拟前端检测电路的低噪声、低失调的要求,介绍一种采用0.18μm CMOS工艺制作的基于斩波稳定技术的可编程增益放大器。采用斩波稳定技术降低失调与低频1/f噪声,利用可编程增益级提高模拟前端电路输出摆幅的利用率,以满足不同环境下的检测需求。该款放大器从1 Hz到10 kHz的等效输入噪声积分值为1.43μV,使用阻抗增强电路实现4.52 GΩ的运放输入阻抗;采用C-2C电容阵列作为可变电容阵列,可实现0~15倍最小步长1/64倍的增益调节,对于需要精细化调节增益的低噪声电路有广泛的应用场景。

高增益高驱动能力的基准电压缓冲芯片的设计

为了解决当前CMOS基准电压缓冲器在驱动大电容负载电路时所面临的可靠性问题和性能瓶颈,提出一种高增益高驱动能力的基准电压缓冲芯片。该芯片采用CMOS缓冲放大器,结构包括折叠式共源共栅输入级、轨至轨Class AB输出级和推挽输出缓冲级。设计中加入了修调电路、Clamp电路及ESD防护电路。芯片面积为2390μm×1660μm。在SMIC 0.18μm CMOS工艺下进行了前仿真、版图绘制及Calibre后仿真。前仿结果显示:当负载电容为10μF时,电路实现了126 dB的高开环增益和97°的相位裕度,同时PSRR超过131 dB,噪声为448 nV/Hz@100 Hz及1 nV/Hz@100 Hz。后仿结果与前仿结果基本一致。总体结果表明,该电路具有高增益、高电源抑制比及低噪声等特点,同时拥有很高的输出驱动能力。因此,所提出的基准电压缓冲芯片可以用于驱动如像素阵列等具有大电容负载的电路。

动态无功补偿装置电压调节增益自动优化研究

针对动态无功补偿装置电压调节器的参数仅能在一定的短路容量范围内保持快速稳定的响应,当应用于短路容量变化范围较大的新能源汇集系统时,响应可能会变得非常慢或出现振荡。提出一种动态无功补偿装置电压调节增益自动优化方法,对应用于实际工程时电压波形畸变、电流波形畸变、其他自动电压补偿装置对短路容量计算结果的影响进行了研究并提出解决方案。在RTDS中对提出的增益自动优化方法进行了仿真研究,结果表明所设计的电压调节增益自动优化方法可以根据系统需求自动调整和优化增益。

半球谐振陀螺电路增益误差分析与校准方法

针对力平衡模式半球谐振陀螺标度因数和零偏受控制电路增益影响的问题,推导了包含控制电路增益的陀螺输出表达式,明确了控制电路增益对陀螺标度因数和零偏的影响机理,提出在控制电路中加入参考信号的增益校准方法,并通过Matlab仿真验证了所提方法的有效性。根据理论计算及仿真结果进行电路设计并开展增益校准实验。实验结果表明,所提校准方法将陀螺的Allan方差最低点由0.006(°)/h降低到了0.002(°)/h,对应陀螺的零偏稳定性提升了3倍。

基于单神经元PID的高增益DC-DC变换器

为使光伏系统和燃料电池的输出电压适应于并网发电系统所需的电压等级,提出一种基于单神经元PID的高增益DC-DC变换器。基于耦合电感的升压单元,使变换器在原有的开关占空比D上,增加一个新的自由度来调节输出电压。钳位单元的引入,削弱了耦合电感漏感与半导体器件的电压尖峰,提升了变换器的效率。通过单神经元PID,增强变换器抗扰动能力。该文先分析所提变换器的工作模态,推出其性能特点,并与经典变换器做出比较。通过仿真模拟电路运行和搭建实验模型研究,验证理论分析的正确性和实验过程的准确性。

一种非隔离型软开关高增益准Z源DC-DC变换器

文中提出一种非隔离型软开关高增益准Z源DC-DC变换器。变换器具有输入电流连续、输入与输出供地、高电压增益以及开关器件应力小等优点。同时,变换器中所有开关管都工作在零电压开关(zero voltage switching,ZVS)条件下,所有二极管都工作在零电压零电流开关(zero-voltage zero-current switching,ZVZCS)条件下,可以减小开关管的开关损耗以及二极管的反向恢复损耗。通过引入三耦合绕组提高变换器电压增益,同时,有源钳位电路的加入减小了开关管两端的电压尖峰。较小感值的耦合电感相应的铜损小、体积小,进而提高了变换器的效率和功率密度。深入分析变换器的工作模态,推导变换器的电压增益以及元器件的电压、电流应力,进行稳态分析和参数设计。最后,搭建一台100 kHz、200 W、38~380 V的实验样机,变换器在额定功率的效率为96.13%,实验结果与理论分析相吻合,证明所提变换器的可行性。

基于并发模型的LAC在线故障检测

针对线性模拟电路的在线故障检测进行了研究。首先,通过对并发测试问题的分析及建模要求,从线性模拟电路的网表描述得到可用于残差生成的扩展状态空间模型,这种扩展的状态空间模型定义了电路的变量/方程依赖矩阵即因果依赖矩阵,进而从因果依赖矩阵可得到电路系统的标称模型和未知输入及故障模型。然后,基于无差拍观测器方法采用扩展的状态模型来生成最优故障检测器的电路方程,从而实现故障的在线残差检测。仿真实验结果表明,与传统的线性模拟电路的离线和在线故障检测方法相比,所提出的方案具有更好的故障检测能力,适用于任何线性模拟电路。

水下磁通信系统研制与调试

文章研究水下磁感应通信技术,旨在为海洋资源开发和环境监测提供一种有效的通信手段。通过对水下磁场特性的分析,设计了磁通信系统,包括发射电路、接收电路以及收发天线。系统采用调幅信号,通过功率放大电路提高发射功率,同时设计了自动增益控制电路以适应不同通信距离。实验在一个80 cm×80 cm×30 cm的玻璃水缸中进行,使用1.6 MHz正弦波信号激励发射线圈,通信距离为0.1~1.0 m。实验结果表明,水介质的导电特性使得水下通信传输距离比空气中更远,但随着涡流损耗的增加,系统的能量损失变得更加明显。

P-型核磁共振成像测井仪GAIN值测量故障分析

MRIL-Prime是哈里伯顿公司新一代的核磁共振成像测井仪器,通常简称为P-型核磁。在应用中发现无增益、增益不稳等常见故障。在实际维修中,必须掌握P-型核磁共振成像测井仪GAIN值的测量原理及中心频率的确定方法。当核磁探头通断绝缘都正常的情况下,增益值不稳或为零,应先检查线路中天线接口模块A2板上的开关管有无损坏,通常情况下增益值不稳或没有,多为A2板上的开关管损坏,更换即可。

Impulsive stabilization of a class of nonlinear system with bounded gain error

Considering mechanical limitation or device restriction in practical application, this paper investigates impulsive stabilization of nonlinear systems with impulsive gain error. Compared with the existing impulsive analytical approaches,the proposed impulsive control method is more practically applicable, which includes control gain error with an acceptable boundary. A sufficient criterion for global exponential stability of an impulsive control system is derived, which relaxes the condition for precise impulsive gain efficiently. The effectiveness of the proposed method is confirmed by theoretical analysis and numerical simulation based on Chua＇s circuit.

A Novel High-Performance Lekage-Tolerant, Wide Fan-In Domino Logic Circuit in Deep-Submicron Technology

As technology shrinks in modern era the demand on high speed, low power consumption and small chip area in microprocessors is come into existence. In this paper we have presented a new class of domino circuit design for low power consumption, faster circuit speed and high performance. Due to wide fan-in domino logic, its logic gate suffer from noise sensitivity, if we improve sensitivity, sub-threshold and gate oxide leakage current dominate in evaluation network, which increases the power consumption and reduces the performance of the circuit. The proposed circuit improves the dynamic power consumption and reduces the delay which improves the speed of the circuit. Simulation is performed in BISM4 Cadence environment at 65 nm process technology, with supply voltage 1 V at 100 MHz frequency and bottleneck operating temperature of 27°C with CL = 1 fF. From the result average power improvement by proposed circuit 1 & 2 for 8 input OR gate is 10.1%, 15.28% SFLD, 48.56%, 51.49% CKD, 55.17%, 57.71% HSD and improvement of delay is 1.10%, 12.76% SFLD, 19.13%, 28.63% CKD, 4.32%, 15.59% HSD, 19.138%, 44.25% DFD respectively.

Nonlinear Modelling of Automatic Gain Control Loops Considering Loop Dynamics and Stability

This work presents modelling aspects of automatic gain control （AGC） loops based on linear-in-dB variable gain amplifiers （VGAs）. In these loops, the VGA control voltage is also an excellent received signal strength indicator （RSSI）. The VGA gain is however nonlinearly related to the control voltage. Moreover, VGAs and detectors undergo nonlinear compression under high input amplitudes during settling transients. The main contribution in this work is a proposed nonlinear model based on simple and readily available components from the ＂analogLib＂ and ＂functional＂ libraries in CADENCE design environment -making it very easy and fast to build and simulate-that captures the nonlinear effects of AGC loops. The model is capable of verifying the AGC loop stability and capturing the loop dynamics with high accuracy compared to time consuming circuit level simulations. This provides insights into system level parameters such as AGC loop bandwidth, phase margin, settling time as well as estimating the AGC range and RSSI voltage vs. input power. Measurement results from a fabricated AGC prototype are in good agreement with simulation and modelling results thus validating the proposed modelling approach.

The Detection of Inter-Turn Short Circuits in the Stator Windings of Sensorless Operating Induction Motors

This work proposes an alternative strategy to the use of a speed sensor in the implementation of active and reactive power based model reference adaptive system (PQ-MRAS) estimator in order to calculate the rotor and stator resistances of an induction motor (IM) and the use of these parameters for the detection of inter-turn short circuits (ITSC) faults in the stator of this motor. The rotor and stator resistance estimation part of the IM is performed by the PQ-MRAS method in which the rotor angular velocity is reconstructed from the interconnected high gain observer (IHGO). The ITSC fault detection part is done by the derivation of stator resistance estimated by the PQ-MRAS estimator. In addition to the speed sensorless detection of ITSC faults of the IM, an approach to determine the number of shorted turns based on the difference between the phase current of the healthy and faulty machine is proposed. Simulation results obtained from the MATLAB/Simulink platform have shown that the PQ-MRAS estimator using an interconnected high-gain observer gives very similar results to those using the speed sensor. The estimation errors in the cases of speed variation and load torque are almost identical. Variations in stator and rotor resistances influence the performance of the observer and lead to poor estimation of the rotor resistance. The results of ITSC fault detection using IHGO are very similar to the results in the literature using the same diagnostic approach with a speed sensor.