A Very High-Speed BiCMOS Replicating Current Comparator for Use in Viterbi Decoders

We describe a low power, asynchronous BiCMOS replicating currentcomparator (RCC) cell for use in analogue Viterbi decoders. The circuitemploys negative feedback to provide an accurate virtual ground for inputcurrent summation and comparison. Thus, although the circuit parasitics arecharged from the power supply as in the case of RCC's with positive feedback, no latching occurs. A resetphase is therefore not required and a more optimal combination of operating speed andresolution can be obtained. Post-layout simulations indicate that the circuit operates inexcess of 150 MHz, can resolve input currents differing by as little as 1A and has a dynamic range in excess of ±200 A. Estimated powerdissipation is about 5 mW per decoder state, drawn from a single 2.8 V powersupply.     

High Output Impedance Current-Mode Four-Function Filter with Reduced Number of Active and Passive Elements Using the Dual Output Current Conveyor

This paper reports a new single-input multi-output current-mode multifunction filter which can simultaneously realise LP, HP, BP and BR filter functions all at high impedance outputs. The circuit permits orthogonal adjustment of quality factor Q and ₀, employs only five grounded passive components and no element matching conditions are imposed. A second order all-pass function can easily be obtained. The passive sensitivities are shown to be low.     

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.     

Analog Circuit Synthesis Using Linear and Nonlinear Current Amplifiers

Various design techniques are presented for obtaining current-mode filters suitable for operation at high frequencies. For this purpose CMOS and or bipolar current amplifiers are used as active building blocks. The derived circuits simulate LC passive prototype filters. Second order resonators can also be obtained by following the same techniques. The presented circuits are modular in structure, thus, their electronic and layout design is very easy. Low-voltage, low-power design is also feasible. Simulation examples for all-pole filters and filters with transmission zeros are given. George Souliotis received the B.Sc. degree in physics from the University of Ioannina, Ioannina, Greece, in 1993 and the M.Sc. and Ph.D. degrees in electronics from the University of Patras, Patras, Greece, in 1998 and 2003, respectively. From 2000 to 2002, he was with Giga Hellas, an Intel company, designing high-speed electronic circuits for transceivers for optical networks. He is co-inventor of a patent that was developed through that work. He is currently a Post-Doctoral Researcher with the Electronics Laboratory, Department of Physics, University of Patras, Patras, Greece. His research interests include analog and mixed signal integrated circuits for high-speed communication applications, current mode circuits, continuous time active filters and CMOS-BiCMOS VLSI design. Nikos Fragoulis was born in Megara Attikis, Greece, in 1972. He received the B.S. degree in physics and the M.Sc. degree in electronics and Ph.D. in electronics from the Electronics Laboratory, Department of Physics, University of Patras, Patras, Greece, in 1995, 1998 and 2005 respectively. He is currently a post-doctoral researcher with the Electronics Laboratory, Department of Physics, University of Patras, Patras Greece. His research interests include, continuous time filtering, and analog integrated circuits for broadband telecommunication applications. Ioannis Haritantis received the Ph.D. in Electronics, in 1976, from the Physics Department, University of Patras, Patras, Greece, in collaboration with the Electrical Engineering Department, Imperial College, London, UK. For many years he has conducted scientific research on the development and design of circuits, discrete component and/or integrated, which are suitable for analog signal processing. His other fields of interest include, network theory, design and testing of integrated circuits, integrated active devices for telecommunications and medical instrumentation, smart sensors, and e-learning. During the past few years his focus is on the design of low-power, low-voltage, tunable, integrated active filters of high dynamic range that could operate at high frequencies. Professor Haritantis in now the director of the Electronics Laboratory, Division of Electronics and Computers, Department of Physics, University of Patras, Patras, Greece. He is also in the editorial board of the journal “Analog Integrated Circuits and Signal Processing”, Kluwer Academic Publishers.     

中值滤波在红外成像引信中的应用及硬件实现

文中研究了在成像引信中应用中值滤波作为一种非线性的图像处理方法及其实现技术。通过运算、试验证明中值滤波在抑制成像引信扫描图像噪声、克服探测元失效方面起着良好的作用。本文提出了一种逻辑选通模块用于硬件实现元素个数较少的中值滤波,不同于常用实现中值滤波的排序网络,其具有更好的并行性且能够降低硬件资源消耗,通过FPGA 实现后取得了良好的效果。     

基于AOA的二阶多功能电流模式滤波器和振荡器

提出了一个二阶多功能电流模式AOA滤波器.该电路仅包含2个AOA,2个电容和7个电阻,能实现各种滤波功能,也能被修饰成一个电流模式振荡器.电路拥有高的精度和高的稳定性,极点频率和品质因数能够被独立、精确地调节.计算机仿真证明该滤波器正确有效.     

Circuit Design of a High Speed and Low Power CMOS Continuous-time Current Comparator

Current comparator is a fundamental component of current-mode analog integrated circuits. A novel high-performance continuous-time CMOS current comparator is proposed in this paper, which comprises one CMOS complementary amplifier, two resistive-load amplifiers and two CMOS inverters. A MOS resistor is used as the CMOS complementary amplifier's negative feedback. Because the voltage swings of the CMOS complementary amplifier are reduced by low input and output resistances, the delay time of the current comparator is shortened. Its power consumption can be reduced rapidly with the increase of input current. Simulation results based on 1.2 m CMOS process model show the speed of the novel current comparator is comparable with those of the existing fastest CMOS current comparators, and its power consumption is the lowest, so it has the smallest power-delay product. Furthermore, the new current comparator occupies small area and is process-robust, so it is very suitable to high-speed and low-power applications.     

Voltage/Current-Mode Universal Filter Using FTFN and CFA

A novel configuration for realizing voltage/current-mode (VM/CM) universal filter using a single four terminal floating nullor (FTFN), a single current feedback amplifier (CFA), two capacitors and three resistors is presented. The VM configuration has three inputs and a single output and implements all the five generic filtering functions through the selection of inputs. This topology enjoys cascadability and does not require any additional active element for facilitating the filter realizations. The same circuit in current-mode has a single input and four outputs and realizes LP, HP and two BP responses simultaneously from which AP and Notch can also be realized. This topology uses grounded resistors and capacitors which are ideal for monolithic integration. Both the topologies enjoy orthogonal control of natural frequency (ω₀) and quality factor (Q) by the grounded resistors. The topologies enjoy low active and passive sensitivity figures. Experimental and PSPICE simulation results are also included.     

Realization of Series and Parallel R-L and C-D Impedances Using Single Differential Voltage Current Conveyor

In this paper, realization of series and parallel R-L immitances using differential voltage current conveyor (DVCC) is presented. The proposed circuits enable actively simulation series and parallel R-L and (-R)-(-L) immitances. Applying RC:CR transformation to the proposed configurations, series and parallel C-D and (-C)-(-D) simulators can also be realized with the same topology. They employ single DVCC and at most three resistors and one capacitor. No component matching constraints are imposed for the realisations. The performance of the proposed immittance simulators is demonstrated on both a second-order voltage and second-order current-mode filters. PSPICE simulations are given to verify the theoretical analysis. An erratum to this article is available at .     

Design of Monolithic Tunable CMOS Band-Pass Filter Using Current Feedback Operational Amplifiers

We propose in this paper a tunable second order band-pass filter based on two CMOS current feedback operational amplifiers (CFOAs). The CFOA includes a novel offset compensation technique. A digital building block is implemented in the proposed band-pass filter to tune its central frequency. An important feature of the adopted tuning procedure is the ability to tune the filter without affecting other characteristics such as gain, phase and quality factor. The band-pass filter topology is validated with a configuration where the central frequency is tuned from 60 MHz to 95 MHz with frequency steps of 5 MHz. Measurements of the offset-compensated CFOA are promising, and simulation results of the CFOA-based band-pass filter using the 0.18 μ m CMOS process confirm our theoretical analysis.     

Low Voltage Rail to Rail CMOS Current Feedback Operational Amplifier and its Applications for Analog VLSI

This paper presents a new CMOS current feedback operational amplifier (CFOA) with rail to rail swing capability at all terminals. The circuit operates as a class AB for lower power consumption. Besides operating at low supply voltages of ±1.5 V, the proposed CFOA has a standby current of 200 A. The proposed CFOA circuit is thus a versatile building block for low voltage low power applications. The applications of the CFOA to realize a transconductor/multiplier cell, MOS-C differential integrator, MOS-C bandpass filter and MOS-C oscillator are given. PSpice simulations based on 1.2 m level three parameters obtained from MOSIS are given.     

基于比特平面的快速中值滤波器设计与实现

提出基于比特平面的快速中值滤波算法硬件实现结构和核心处理电路,在减少了中值滤波电路面积的情况下,显著提高了处理速度.提出的比特平面算法硬件实现结构的面积与滤波数据长度和量化比特教成近似线性关系,适于各种滤波窗口大小和数据精度的中值滤波;算法硬件实现结构规则,特别适于用FPGA实现.     

小波中值滤波在晃动基座初始对准中的应用

针对捷联惯性导航系统(SINS)在晃动基座下进行初始对准时,陀螺和加速度计受外界干扰噪声较大,而单独采用低通滤波或小波滤波法不能有效实时地实现噪声抑制问题,采用小波阈值消噪和中值滤波相结合的混合滤波方法来实现信号的消噪。将输出信号首先经中值滤波消除信号中的突变噪声,再利用小波阈值消噪滤除振动噪声和白噪声,从而有效地消除基座晃动带来的噪声。测试实验表明,提出的混合滤波法对车载惯导系统输出信号噪声滤波效果明显,在发动机启动的情况下,可基本达到静态信号采集的效果。对准仿真实验表明,提出的滤波法能辅助捷联惯导系统实现在晃动基座下的精对准。     

Control and Observation Structure for Analog Circuits with Current Test Data

This work presents a current-mode control and observation structure (CMCOS) for analog circuits with current test data. Current store cells (CSCs) are used in the proposed CMCOS to enhance the controllability and observability. The proposed CMCOS can be used to observe several test points, which can be simultaneously sampled and controlled using current test data. Additionally, the proposed CMCOS enables designers to use one channel of an oscilloscope to monitor simultaneously several output waveforms of analog circuits or systems. The physical chip of a two-stage CMCOS was fabricated using TSMC 1P4M CMOS 0.35 um technology. Also, experiments were performed to confirm the theoretical analysis.     

通用有源电流模式滤波器及其仿真

采用信号流图设计了由两个 OTA和一个 MOCC + / -构成的三输入一输出电流模式二阶滤波器新电路 ,合理选择输入电流可实现低通、高通、带通、带阻及全通滤波功能。所提电路结构简单 ,中心频率ω0 和品质因数 Q独立可调 ,无源元件全部接地 ,滤波器特性参数对无源元件灵敏度低。理论分析和 MOS管级的 PSPICE仿真表明所提电路方案正确     

GaAs FET Current-Mode Integrators and Their Application to Filters

In this paper, current-mode integrators which consist of only n-channel depletion-mode FET and their application to filters are presented. Lossy integrator is simply realized with a capacitor and a grounded gate FET. Lossless integrator can be obtained by providing a lossy integrator with a positive feedback. To do this, multi-output current mirror is proposed. To reduce 2nd-order harmonic and THD of the filter, unbalanced/balanced conversion circuit is proposed. As an application example, 3rd-order leapfrog low-pass Chebyshev filter is simulated with GaAs MESFET process parameters. Simulation results show good performances.     

Current‐Mode Electronically Tunable Universal Filter Using Only Plus‐Type Current Controlled Conveyors and Grounded Capacitors

In this paper we present a new current‐mode electronically tunable universal filter using only plus‐type current controlled conveyors (CCCII+s) and grounded capacitors. The proposed circuit can simultaneously realize lowpass, bandpass, and highpass filter functions—all at high impedance outputs. The realization of a notch response does not require additional active elements. The circuit enjoys an independent current control of parameters ω₀ and ω₀ / Q. No element matching conditions are imposed. Both its active and passive sensitivities are low.     

Analysis and Compensation of Log-Domain Biquadratic Filter Response Deviations due to Transistor Nonidealities

A translinear log-domain integrator, the powerhouse of log-domain filtering techniques, is analyzed to determine its deviations due to major time-invariant bipolar transistor imperfections, such as parasitic emitter and base resistances, finite beta, Early effect, and area mismatches. The results are used to predict the transfer function deviations of biquad filters, for both lowpass and bandpass filter responses. It will be shown that the errors can be understood and categorized into integrator scalar and negative feedback errors, and how they can be electronically compensated. SPICE simulations, both large and small-signal analysis, are performed to verify the results.     

A New CMOS Programmable Balanced Output Transconductor and Application to a Mixed Mode Universal Filter Suitable for VLSI

A new CMOS programmable balanced output transconductor (BOTA) is introduced. The BOTA is a useful block for continuous-time analog signal processing. A new CMOS realization based on MOS transistors operating in the saturation region is given. Application of the BOTA in realizing a mixed mode universal filter using six BOTAs and two grounded capacitors is also introduced. The filter's gain can be adjusted simply by varying the amplitude of a transconductance through its control voltage without affecting ₀ and Q of the filter. Also, the Q of the filter can be adjusted by a single transconductor independent of ₀. PSpice simulation results for the BOTA circuit and for the universal filter are also given.     

深槽隔离及其在双极型电路中的应用

本文简要回顾了双极型集成电路隔离技术的发展,着重分析讨论了八十年代发展起来的深槽隔离技术及其在双极型集成电路中的应用。