一种适用于生物电信号处理的全集成五阶Gm-C低通滤波器

传统的Gm-C滤波器OTA输入晶体管大多工作在饱和区,存在输入动态范围较小和跨导值较大等不足,难以满足生物医学电信号处理滤波器所要求的超低截止频率、低功耗与大输入动态范围等要求,采用将输入晶体管钳位到线性工作区的方法,设计了跨导线性可调的OTA以提高滤波器能够处理的信号幅度。并应用该OTA综合了一种五阶Gm-C超低频低通滤波器。仿真结果表明,该滤波器在1.8 V电源,800 m Vpp输入条件下实现了283 Hz的超低低通角频率,-6.4 d B的带内增益,51 d B的三次谐波失真,功耗仅为22μW,适用于可穿戴式生物医学电信号读取电路。     

基于粒子群优化算法的工频陷波滤波器的设计

阐述一种基于粒子群算法的50Hz工频陷波滤波器优化设计,依据工频陷波滤波器的幅频响应与理想幅频响应之间均方误差最小化原则,采用粒子群算法,计算陷波滤波器的系数。     

任意阶OTA-C多功能滤波器的设计。

提出了一种新的任意阶运算跨导放大器——电容(OTA-C)多功能滤波器的设计方法。通过将n阶传递函数分解为n+1个一阶传递函数,导出了任意阶传递函数OTA-C实现电路。适当选择各输入端电压,可实现低通、高通、带通、带阻、全通等滤波功能。文中给出了6阶滤波器设计实例,PSPICE仿真结果与理论分析相吻合,验证了设计方法的可行性。     

用于红外接收芯片的OTA-C带通滤波器

设计了一种二阶带通连续时间滤波器(BPF),采用0.5μm n阱CMOS工艺设计,在Cadence Spectre环境下进行了电路仿真。结果表明:该滤波器的中心频率38kHz,带宽6kHz,通带增益16dB且均匀可调,可用于红外接收芯片中。     

电流模式高阶OTA-C高通滤波器的设计

提出了一种新的电流模式高阶OTA—C高通滤波器的设计方法。由该方法导出的滤波器具有最少的元件．n阶滤波器仅需n个OTAs和n个电容，所有的电容均接地，便于集成且与VLSI工艺兼容。文中给出了6阶滤波器设计实例，PSPICE仿真结果与理论分析相吻合，验证了该设计方法的可行性。     

运算跨导放大器(OTA)椭圆高通滤波器设计

本文提出了OTA椭圆高通滤波器的设计方法。基于无源RLC高通梯型网络的节点电压模拟,系统地生成了由三类网络和五种接阻终端组合构成的所有可能的OTA高通滤波器结构。     

基于OTA-C的多功能全集成电流模式双2阶滤波器

采用TSMC 0.18 μm CMOS工艺,设计了一种基于OTA的单输入多输出的多功能电流模式双2阶滤波器。滤波器的5个输出端口可同时得到低通、高通、带通、带阻和全通5种滤波功能。该电路结构简单,仅需要4个MO-OTA和2个电容;电路固有角频率ω₀及品质因数Q值独立可调;灵敏度低,均小于或等于0.5。基于BSIM3模型参数,采用Hspice仿真工具对电路进行了仿真,结果表明滤波器性能良好,版图符合设计要求。     

用于ECG的低通带衰减OTA-C滤波器设计

以心电图(ECG)检测为应用背景,采用电流互抵技术和线性区晶体管偏置结构设计了一种超低跨导、高线性度的跨导运算放大器(OTA),其跨导达到了nA/V量级。在此基础上,根据信号传输函数搭建了一个4阶低通滤波器电路模型,其截止频率为250 Hz,通带衰减为0.4 dB,带内平均噪声为90.53 μV(rms)·Hz-1/2,在ECG应用中拥有67 dB的动态范围(THD≤1%)。使用Cadence Spectre软件进行仿真和调试,最后进行版图设计并流片。在不包括静电结构和压焊点的情况下,芯片版图面积为0.027 mm²。电路供电电压为1.8 V,具有很高的集成度,能应用于便携式ECG集成电路中。     

可变带宽OTA—C连续时间低通滤波器设计

实现了一种全集成可变带宽中频宽带低通滤波器,讨论分析了跨导放大器-电容（OTAc）连续时间型滤波器的结构、设计和具体实现,使用外部可编程电路对所设计滤波器带宽进行控制,并利用ADS软件进行电路设计和仿真验证。仿真结果表明,该滤波器带宽的可调范围为1～26MHz,阻带抑制率大于35dB,带内波纹小于0．5dB,采用1．8V电源,TSMC 0．18μm CMOS工艺库仿真,功耗小于21mw,频响曲线接近理想状态。     

新型脑电信号放大检测电路的设计

通过对前置放大器等电路结构的精心设计,选用超低噪声的集成运算放大器以及线性光耦合器等新器件,克服了脑电信号采集中常遇到的一些困难,使前置放大器具有较高的共模抑制比,从而能够较好地放大检测出的脑电信号.通过Pspice仿真软件,有助于电路的设计和调试.     

基于衬底驱动技术的0.8 V三阶椭圆 OTA-C滤波器

基于衬底驱动MOS技术,设计了一种0.8 V高性能全差分CMOS跨导运算放大器(OTA)。在互补输入差分对的衬底端施加信号,避开MOSFET阈值电压的限制,以达到超低压应用。在0.8 V的电源电压下,其直流开环增益为73.8 dB,单位增益带宽为16.4 MHz。基于该OTA,采用无源网络模拟法,设计实现了截止频率为5 MHz,通带波纹为0.5 dB的三阶椭圆OTA-C滤波器。仿真结果表明了所设计滤波器的正确性。     

一种适用于心电信号检测的高阶连续时间OTA-C滤波器设计

提出一种适合心电信号（ECG）检测的OTA-C滤波器。为了达到低功耗、低截止频率、高直流增益、高阻带衰减、低谐波失真的目的,滤波器采用五阶巴特沃斯全差分低通滤波结构和高增益的两级单端输出OTA,其中OTA电路采用亚阈值区驱动、电流分流和源极负反馈等技术。采用SMIC 0.18-μm 1P6M CMOS工艺进行电路、版图设计及优化。仿真结果表明,滤波器在静态功耗为17.6 μW,截止频率为240 Hz,直流增益为-6 dB,阻带衰减为120 dB每十倍频,三次谐波失真小于-62 dB@ 400 mV,适合应用于心电信号检测模拟前端。     

A Low-Power 3V Lowpass OTA-C Filter for Megahertz Range

By applying a signal-flow graph (SFG) based filter synthesis an active OTA-C topology for integration of a 5-degree elliptic lowpass (LP) filter has been designed. The dynamic range has been maximized for this single-ended OTA-C filter, which has floating capacitors. This has been done through the use of an optimizing circuit simulator. Thus low-voltage (3V) operation despite high signal amplitudes (1V_pp) has been achieved. A linearized operational transconductance amplifier (OTA) has been designed and optimized for the filter. For comparison purposes the single-ended design has been converted to a fully differential one with an additional +6dB of gain. Integrated filters realized with a 1.2 m CMOS process have been thoroughly measured. The filters are especially applicable for mobile communications because of low power consumption.     

一种适用于生理信号的OTA-C滤波器

设计了一种全集成频率可调的OTA-C滤波器,主要应用于低频率生理信号的处理。其中,跨导放大器(OTA)采用串并联金属氧化物半导体场效应晶体管(MOSFET)阵列结构。通过改变外部控制电压,进而改变OTA的跨导值,可以实现滤波器截止频率可调。滤波器采用标准的0.18 μm CMOS工艺,电源电压为1.8 V。当OTA的偏置电流为0.01 μA时,其等效跨导低至1.3×10-10 S,得到OTA-C滤波器的截止频率为0.2 Hz。调节外部电压,使偏置电流在0.01~0.5 μA之间变化,OTA的等效跨导值为1.3×10-10~1.2×10-9 S,OTA-C的截止频率为0.2~2 Hz。     

用SFG法设计OTA－C滤波器

本文提出了由传递函数的信号流图（ＳＦＧ）直接设计ＯＴＡ－Ｃ滤波器的方法。成功的设计了未见发表的３种一阶电路和３种二阶电路，为ＯＴＡ－Ｃ滤波器的设计提供了一简捷、直观的方法。     

Cascode Monolithic DC-DC Converter for Reliable Operation at High Input Voltages

A CMOS OTA-C low-pass notch filter for EEG application is described. The pass-band covers four bands of brain wave and provides more than 65 dB attenuation for the 50 Hz power line interference. The OTA works in the weak inversion region and a low transconductance of 3 nA/V is achieved. The low transconductance enables using small capacitors in the OTA-C filter so that the filter is suitable for the multi-channel EEG integrated circuits. The measured results show the good performance of the filter for filtering the noise in acquired EEG signals. Xinbo Qian received the B.Sc. degree from Beijing Institute of Technology, P.R. China, in 1991 and M.Sc. degree from Institute of Physics, Chinese Academy of Sciences, in 1996. From 1996 to 1999, she was a research engineer in the Institute of Acoustics, Chinese Academy of Sciences, worked on the sonar signal receiving and processing systems. Since 1999, she has been pursuing the Ph.D. degree in Electrical and Computer Engineering department, National University of Singapore, with research direction on on-chip readout circuits for microbolometer focal plane arrays. Now she is employed by Department of Mechanical Engineering and Division of Bioengineering, National University of Singapore as a research fellow. Her research interest is low-noise integrated circuits design and bio-medical sensor electronics, including electroencephalography IC, magnetocardiography IC, low-noise amplifier, filter and data converters etc. Yong Ping Xu graduated from Nanjing University, P.R. China in 1977. He received his Ph.D. from University of New South Wales (UNSW) Australia, in 1994. From 1978 to 1987, he was with Qingdao Semiconductor Research Institute, P.R. China, initially as an IC design engineer, and later the deputy R&D manager and the Director. From 1989 to 1992, he was working on silicon diode based infrared detectors towards his Ph.D. at School of Electrical Engineering, UNSW Australia. From 1993 to 1995, he worked on an industry collaboration project with GEC Marconi, Sydney, Australia, at the same university, involved in design of sigma-delta ADCs. He was a lecturer at University of South Australia, Adelaide, Australia from 1996 to 1998. He has been with the Department of Electrical and Computer Engineering, National University of Singapore since June 1998 and is now an Associate Professor. His general research interests are in the areas of mixed-signal and RF integrated circuits, and integrated MEMS and sensing systems. His current focuses are high-speed wideband ADC, UWB front-end circuits and low-power low-voltage integrated circuits for biomedical applications. He is a Senior Member of IEEE. Xiaoping Li received his Ph.D. degree from Department of Mechanical and Manufacturing Engineering, University of New South Wales, Australia in 1991, and joined the National University of Singapore in 1992, where he is currently an Associate Professor with the Department of Mechanical Engineering and Division of Bioengineering. He was a visiting professor of Tokyo Institute of Technology, Japan in 2000, and visiting professor of Georgia Institute of Technology, USA in 2001. He is a member of American Society of Mechanical Engineers (ASME), a senior member of Society of Manufacturing Engineering (SME) and a senior member of North American Manufacturing Research Institute/SME, and is currently the Chairman of SME Singapore Chapter. His current research interests include neurosensors and nanomachining. He is a guest editor of International Journal of Computer Applications in Technology, USA. He is a regular reviewer of the ASME Journal of Manufacturing Engineering, USA, Transactions of NAMRI/SME, USA, Journal of materials processing technology, UK, International Journal of Machine Tools and Manufacture, UK, and IMechE Journal of Engineering Manufacture, UK.     

一种新的通用高阶OTA-C滤波器的设计

本文提出以传递函数的信号流图实现为基础,设计出一种新的通用高阶可调OTA-C滤波器.该滤波器仅需要OTA器件和接地电容,适合于用MCS技术实现.实验结果证明了它的可行性.     

基于复数陷波器的窄带干扰抑制研究

研究了直接序列扩频通信系统中幅值相差较大的窄带干扰抑制问题,以一阶复数自适应陷波器为陷波单元,介绍了一种级联结构的陷波器,给出了系数迭代的自适应算法和理论分析。仿真实验表明,该陷波器能有效消除多个窄带干扰,迭代算法具有良好的收敛性能。     

一种低功耗自动频率修正的复数滤波器设计

采用当前主流的0.18μm RFCMOS工艺,设计实现了一款低功耗五阶OTA-C复数滤波器电路,该电路应用于低中频结构的GPS射频前端芯片中。滤波器的频率修正电路没有采用基于锁相环的常规结构,而是设计了一种带有频率修正功能的自偏置电流基准,来补偿工艺、温度变化的影响。滤波器的带宽为3MHz,中心频率为4.092MHz,镜像抑制大于30dB,10MHz频率处的阻带抑制大于40dB。滤波器的通带增益为10dB,消耗的总电流为0.8mA,工作电压为1.8V。理论仿真结果和测试结果能够很好地符合。     

抗干扰用陷波滤波器

详细介绍了采用Ｒｅｍｅｚ算法和最小二乘法综合带陷波点频响滤波器的设计方法,并给出了设计制作的７０ＭＨｚ陷波滤波器结果。