锁相环频率合成器中的电荷泵设计

用TSMC 0.18μm CMOS工艺设计了一种电荷泵电路。传统的电荷泵电路中充放电电流有较大的电流失配,文章采用与电源无关的基准电流源电路,运用运算放大器和自偏置高摆幅共源共栅电流镜电路实现了充放电电流的高度匹配。仿真结果表明:电源电压1.8V时,电荷泵电流为0.5mA;在0.3V～1.6V输出电压范围内电流失配小于1μA,功耗为6.8mW。     

低杂散锁相环中的电荷泵设计

用TSMC0.18μm CMOS工艺设计并实现了一种电荷泵电路，传统的电荷泵电路中充放电电流有较大的电流失配,电流失配导致相位偏差,从而引起杂散并降低了锁相环的锁定范围，文中采用与电源无关的基准电流源电路,运用运算放大器和自偏置高摆幅共源共栅电流镜电路实现了充放电电流的高度匹配,从而降低了杂散。测试结果表明：电源电压1.8V时,电荷泵电流为0.475mA,在0.3-1.6V输出电压范围内电流失配小于10mA,功耗为6.8mW。     

高性能电荷泵电路设计与HSPICE仿真

电荷泵锁相环具有高速、低功耗、低抖动等特点.电荷泵是锁相环中的关键模块,它实质上是一个开关电流源,需具有精准稳定的恒流源和理想的开关.在模块运行中,一般会出现电荷共享及充放电电流不匹配等现象.通过自举的方法,可以较好地消除电荷共享现象;采用电流跟随电路,可以使充放电电流得到较好匹配.基于2.5 V 0.25 μm CMOS工艺,设计了一个高性能电荷泵.采用Synopsys公司的Hspice仿真软件,对设计的电路进行模拟仿真.结果显示,在1.45 V至2.0 V之间,充放电电流几乎相等.     

低杂散锁相环中的电荷泵设计

用TSMC 0.18μm CMOS工艺设计并实现了一种电荷泵电路.传统的电荷泵电路中充放电电流有较大的电流失配,电流失配导致相位偏差,从而引起杂散并降低了锁相环的锁定范围.文中采用与电源无关的基准电流源电路,运用运算放大器和自偏置高摆幅共源共栅电流镜电路实现了充放电电流的高度匹配,从而降低了杂散.测试结果表明:电源电压1.8V时,电荷泵电流为0.475mA,在0.3～1.6V输出电压范围内电流失配小于10mA,功耗为6.8mW.     

一种应用于锁相环的增益提高型电荷泵设计

采用0.18μm 1.8V CMOS工艺设计一种增益提高型电荷泵电路,利用增益提高技术和折叠式共源共栅电路实现充放电电流的匹配.该电荷泵结构可以很大程度地减小沟道长度调制效应的影响,使充放电电流在宽输出电压范围内实现精确匹配,同时具有结构简单的优点.仿真结果表明,电源电压1.8V时,电荷泵电流为600μA,在0.3～1.6V输出范围内电流失配为0.6μA,功耗为3mW.     

锁相环中高性能电荷泵的设计

设计了一种结构新颖的动态充放电电流匹配的电荷泵电路，该电路利用一种放电电流对充电电流的跟随技术，使充放电电流达到较好匹配，同时，在电荷泵中增加差分反相器，提高电荷泵的速度。采用Istsilicon 0．25μmCMOS工艺进行仿真，结果显示：输出电压在0．3—2．2V之间变化时，电荷泵的充放电电流处处相等。     

一种用于PLL的新型电荷泵结构

本文设计了一种适用于PLL的新型电荷泵电路,将MOS开关置于源极,抑制电荷共享和电荷注入,并且采用可调节共源共栅结构增大输出阻抗,用于抑制电流失配。同时该电路具有结构简单、功耗低、充放电速度快等特点。采用Charter 0．35μm CMOS工艺模型,Mentor Graphics公司的Eldo进行仿真,在电荷泵输出电压范围为0．5～2．8V内,充放电电流匹配良好。     

基于常数跨导轨到轨运算放大器的新型电荷泵

针对传统电荷泵电荷共享引起的输出电压波动、充放电电流失配引起的电路杂波问题,设计了一种新型电荷泵。该电荷泵电路采用常数跨导轨到轨运算放大器,降低了电荷共享引起的输出电压波动;采用基于全差分放大器的负反馈结构,解决了充放电电流失配的问题。基于SMIC 0.18 μm CMOS工艺,利用Cadence软件完成了电路的设计与仿真。结果表明,在0.5～1.5 V输出电压范围内,该电荷泵充放电电流失配小于2%;与传统电荷泵相比,该电荷泵输出电压的波动减小了1.5 mV,并且采用该电荷泵的锁相环输出频谱噪声减小了10 dB。     

一种改进型高性能电流舵电荷泵电路设计

提出一种改进型高性能单端电荷泵电路 ,该电路基于电流舵结构 ,使用运放将偏置电路与充放电电路分开。该电路具有低的输出抖动、宽的电源范围 ,使用级连电流镜像消除过冲注入电流。基于 CMOS0 .3 5工艺 ,用 SPECTRE对该电路进行仿真 ,改进后的电路可消除 1.2 m A的注入电流 ,稳定工作在 2 5 /12 .5 MHz下 ,其最低工作电压为 2 .2 V,静态功耗为 0 .44m A,达到设计目标。     

一种锁相环中高性能电荷泵电路

设计了一种新型电荷泵电路.该电荷泵电路采用可调节共源共栅结构增大输出阻抗,具有结构简单、速度快、充放电电流匹配性好、抑制了电荷注入等特点.采用0.18μmCMOS工艺模型以及Hspice仿真工具的仿真结果显示,输出电压在0.4~1.3V之间变化时,电荷泵的充放电电流处处相等.     

Using High Frequency Operational Amplifiers for Low Noise Design

In this paper we present a comprehensive noise and stability analysis of both the current feedback and the voltage feedback op-amp when connected as transimpedance amplifiers with capacitive current sources. It is generally assumed that the current feedback op-amp is noisier than the voltage feedback op-amp; we show how external component values play an important role in determining the total equivalent input noise current spectral density and show that the voltage feedback op-amp may, in certain cases, be noisier than the current feedback op-amp. Both amplifier types are compared in terms of stability, noise and bandwidth; we find that the current feedback op-amp is particularly suited for operation as a transimpedance amplifier. Theoretical analysis is confirmed by simulations of equivalent circuits of the current feedback op-amp and the voltage feedback op-amp, and simulations of the macro models of two high performance commercially available op-amps, namely the Elantec EL2260 current feedback op-amp and the Elantec EL2244 voltage feedback op-amp.     

An integrated low-voltage class AB CMOS OTA

We present a new circuit topology for a low-voltage class AB amplifier. The circuit shows superior current efficiency in the use of the supply current to charge and discharge the output load. It uses negative feedback rather than component matching to optimize current efficiency and performance, resulting in a current boost ratio exactly equal to one. Measurement results for an example circuit fabricated in a 2-μm CMOS process are given. The circuit uses a quiescent supply current of 0.2 μA and is able to settle to a 1% error in 1.1 ms for a 0.4-V input step and a load capacitance of 35 pF. The circuit design is straightforward and modular, and the core circuit can be used to replace the differential pair of other op-amp topologies     

一种新型电荷泵电路的设计

文章提出了一种新的全差分电荷泵结构，与传统电荷泵电路相比，这个电路具有输出范围大和无跳跃现象的优点，同时还可以有效地解决电荷泄漏和充放电失配等问题。     

Correlation investigation between contact approach speed of handheld metal rod and discharge parameters from charged human body

Characteristic measurement of contact discharge currents are made through a hand-held metal rod from charged human body. Correlation coefficients are obtained, through Statistic Package for Social Science （SPSS）, for various charge voltages, which is based on the effect test of electrode contact approach speeds on discharge current parameters of current peaks, maximum rising slope and spark lengths. Discharge parameters at charge voltage 300V are independent on approach speed. For charge voltages equal to and higher than 500V, the contact approach speed has strong positive correlation with discharge parameters of the peak current and the maximum rising slope, whereas has strong negative correlation with the spark length.     

基于UTB-SOI技术的双辅助触发SCR ESD防护器件研究

为了提高FDSOI ESD防护器件的二次击穿电流,基于UTB-SOI技术,提出了一种SOI gg-NMOS和寄生体硅PNP晶体管双辅助触发SCR器件。通过gg-NMOS源区的电子注入和寄生PNP晶体管的开启,共同辅助触发主泄放路径SCR,快速泄放ESD电流。TCAD仿真结果表明,新结构能够泄放较高的二次击穿电流,具有可调节的触发电压。     

A Novel Bandpass Filter Based on Current Feedback Amplifier

An application demonstrating some advantages of the current feedback amplifier (CFA) over the voltage op-amp counterpart is given. A novel bandpass filter achieving a high quality factor and variable gain based on a single CFA is proposed. It is shown that unlike the op-amp Sallen-Key bandpass filter, the CFA filter is more suitable for high frequency applications. Hussain A. Alzaher was born in Qatif-Alawamia, Saudi Arabia, in 1972. He received the B.S. and M.S. degrees (with honors) in electrical engineering from King Fahd University of Petroleum and Minerals (KFUPM), Dhahran, Saudi Arabia, in 1994 and 1997, respectively, and the Ph.D. degree from The Ohio State University, Columbus, in 2001. Since 1994, he has been with KFUPM as a faculty member in the electrical engineering department. His research interest includes applications of electronic circuit techniques for wireless communications: Multi-standard mobile phones, Bluetooth, WLAN and WiMAX. Dr. Alzaher is the recipient of the 1994/1995 Prince Muhammed bin Fahd bin Abdulaziz Award for Excellence in Scientific Achievement. He is also the recipient of the 2003 Showman award for Young Arab Researchers, Engineering Science.     

高稳定度光纤耦合半导体激光器恒流源电路设计

光纤耦合半导体激光器多用作高功率光纤激光器的泵浦源,它对电流波动十分敏感,为了确保其波长与输出功率的正常,设计了一款高稳定度恒流源电路。此恒流源电路采用闭环反馈控制,使MOS管工作在放大区来输出恒定电流,采用带有透孔的厚膜电阻作为采样电阻,其耐压高、阻值范围宽、散热能力强,大大提高了恒流源电路的稳定性,电路实现0~20 A电流可调。鉴于一般恒流源电路启闭时间较长,此电路在运放与MOS管之间加入晶体管来放大信号,缩短电路启闭时间,同时在设计中增加模拟开关电路来精确控制信号。经实验测试,此恒流源电路开启、关闭耗时较短,分别是4.5 ms与6.5 ms,恒流板结构散热能力较强且稳定,耐高温性好,电流稳定度较高,达到10-3量级,使用此电路设计的电源作为光纤耦合半导体激光器的激光电源时,激光器的中心波长与输出功率均较为稳定。