一种高增益宽带共栅CMOS电流模跨阻放大器

文章提出了一种高增益宽带共栅CMOS电流模跨阻放大器，从理论上对电路进行了分析。采用0．5μm CMOS工艺进行HSPICE仿真，结果表明，该电路结构能达到57dBΩ跨阻增益，1．5GHz带宽，6．4pA／sqrt(Hz)等效输入总电流噪声；在输入电流为200pA时，其输出电压的动态摆幅达到220mV，功耗仅为76mW。     

A CMOS Low-Dropout Regulator With Current-Mode Feedback Buffer Amplifier

Current feedback amplifiers (CFAs) provide fast response and high slew rate with Class-AB operation. Fast response, low-dropout regulators (LDRs) are critical for supply regulation of deep-submicron analog baseband and RF system-on-chip designs. An LDR with an CFA-based second stage driving the regulation field-effect transistor is presented. The low dropout (LDO) achieves an output noise spectral density of 67.7 nV radicHz, and PSR of 38 dB, both at 100 kHz. In comparison to an equivalent power consumption voltage feedback buffer LDO, the proposed CFA-based LDO settles 60% faster, achieving 0.6- settling time for a 25-mA load step. The LDO with CFA buffer is designed and fabricated on a 0.25- CMOS process with five layers of metal, occupying 0.23- silicon area.     

基于CMOS MOCCCII的电调谐电流模式多功能滤波器

设计了一种基于CMOS多输出第二代电流控制传输器 (MOCCCII) 的可调谐电流模式双输入、多输出多功能滤波器.该滤波器仅由两个CCCII、一个接地电阻和两个接地电容组成.选择输出端中的一个或它们的组合,即可实现低通、带通、高通、带阻和全通5种二阶滤波功能.电路结构简单,且固有频率ωo和品质因数Q可独立调节;具有较低的有源和无源灵敏度.HSPICE仿真结果表明,设计的电路是正确的.     

基于MO-CDTA的电控调谐多功能电流模式二阶滤波器/振荡器

描述了一个基于多输出电流差分跨导放大器(MO-CDTA)的多功能电流模式二阶电路.该电路仅使用四个MO-CDTA和两个接地电容,能同时和分别实现高通、带通和低通电流传输函数,电路的极点频率和品质因素能独立地被电控调节;电路也能被修饰成一个电流控制的正弦振荡器.计算机仿真表明电路正确有效.     

A CMOS Low-Noise Instrumentation Amplifier Using Chopper Modulation

This paper describes a low-power, low-noise chopper stabilized CMOS instrumentation amplifier for biomedical applications. Low thermal noise is achieved by employing MOSTs biased in the weak/moderate inversion region, whereas chopper stabilization is utilized to shift 1/f-noise out of the signal band hereby ensuring overall low noise performance. The resulting equivalent input referred noise is approximately 7 nV/ ?{Hz}\sqrt{\rm Hz} for a chopping frequency of 20 kHz. The amplifier operates from a modest supply voltage of 1.8 V, drawing 136 A of current thus consuming 245 W of power. The gain is 72.5 dB over a 4 kHz bandwidth. The inband PSRR is above 90 and the CMRR exceeds 105 dB.     

A CMOS Low-Noise Instrumentation Amplifier Using Chopper Modulation

This paper describes a low-power, low-noise chopper stabilized CMOS instrumentation amplifier for biomedical applications. Low thermal noise is achieved by employing MOSTs biased in the weak/moderate inversion region, whereas chopper stabilization is utilized to shift 1/f-noise out of the signal band hereby ensuring overall low noise performance. The resulting equivalent input referred noise is approximately 7 nV/ for a chopping frequency of 20 kHz. The amplifier operates from a modest supply voltage of 1.8 V, drawing 136 A of current thus consuming 245 W of power. The gain is 72.5 dB over a 4 kHz bandwidth. The inband PSRR is above 90 and the CMRR exceeds 105 dB.Jannik Hammel Nielsen was born in Nuuk, Greenland, in 1972. He received the M.Sc. and Ph.D. degrees in electrical engineering in 1999 and 2004 respectively, from the Technical University of Denmark. He is presently employed as a postdoctoral researcher at ØrstedDTU.His main research interests are in low-voltage, low-power analog systems, medical electronics and data converters.Erik Bruun received the M.Sc. and Ph.D. degrees in electrical engineering in 1974 and 1980, respectively, from the Technical University of Denmark. In 1980 he received the B.Com. degree from the Copenhagen Business School. In 2000 he also received the dr. techn. degree from the Technical University of Denmark.From January 1974 to September 1974 he was with Christian Rovsing A/S, working on the development of space electronics and test equipment for space electronics. From 1974 to 1980 he was with the Laboratory for Semiconductor Technology at the Technical University of Denmark, working in the fields of MNOS memory devices, I²L devices, bipolar analog circuits, and custom integrated circuits. From 1980 to 1984 he was with Christian Rovsing A/S. From 1984 to 1989 he was the managing director of Danmos Microsystems ApS. Since 1989 he has been a Professor of analog electronics at the Technical University of Denmark where he has served as head of the Sector of Information Technology, Electronics, and Mathematics from 1995 to 2001. Since 2001 he has been head of ØrstedDTU.His current research interests are in the areas of RF integrated circuit design and integrated circuits for mobile phones.     

可调增益均衡性宽带MMIC低噪声放大器设计

文章提出了一种新颖的具有可调增益均衡特性的宽带全单片低噪声放大器电路设计方法,它将用于微波功率模块(MPM)的固态功率放大器(SSPA)链前端中的两项功能独立的电路(多级单片宽带低噪声放大器LNA和单片宽带频率均衡放大器FEA)组合设计在一块单片电路芯片中。其中LNA部分采用高效率高增益宽带级联型分布放大器取代常规的行波式分布放大器,使得放大器级数显著减少;频率均衡放大器提出用一种利用FET作可调元件的嵌入式低损无源网络来取代,使得放大器的增益特性在频带中部下凹可调,补偿了行波管“山丘状”功率增益特性。在此基础上完成设计的 MMIC LNA,仅使用3个0．25μm×120μm pHEMT,在6GHz～18GHz频带内,小信号增益14．3 ±0．8 dB,输入、输出反射损耗<-10 dB,NF<5 dB;嵌入可调增益均衡网络后,在其他性能参数基本保持不变的前提下,频带中部引入的电调衰减范围超过6．5 dB,完全满足MPM要求。     

A Differential CMOS Current-Mode Variable Gain Amplifier with Digital dB-Linear Gain Control

A novel CMOS variable gain amplifier operating on current signals with a dB-linear gain control is presented. The gain control is achieved by multiplying a digitally synthesized exponentially varying control current signal by a differential input signal in the current domain. A current amplifier at the output sets the gain to the desired level. Current-mode operation allows for a reduced supply voltage by minimizing the voltage swing at the low impedance nodes of the circuit. Multiple circuit realizations for various blocks are presented allowing for designs meeting different constraints. Experimental realization of the variable gain amplifier shows the validity of the presented approach.     

Current-Mode First-Order Allpass Filter Employing Single Current Operational Amplifier

A current-mode first-order allpass filter configuration is proposed. The presented circuit uses a single current operational amplifier (COA), a resistor and a capacitor, which are of minimum number. High output impedance of the proposed filter enables the circuit to be cascaded without additional buffers. The proposed circuit is insensitive to parasitic input capacitances and input resistances due to internally grounded input terminals of COA. It does not impose any component matching constraint in analog signal processing circuits. Non-ideal effects of COA to the first-order allpass network are also investigated. To demonstrate the performance of the proposed filter a new current-mode quadrature oscillator is given as an application example. The theoretical results are verified with PSPICE simulations using a new realization of fully differential CMOS COA.     

基于CDBA的电流模式多功能滤波器

文章提出了一种由电流差分缓冲放大器（CDBA）实现的两种电流模式多功能双二次滤波器，该滤波器具有可实现多种滤波功能、能独立地调节ω0和Q、灵敏度较低等特点。     

如何构建仪表放大器

仪表放大器是在有噪声的环境下放大小信号的器件。它利用的是差分小信号叠加在较大的共模信号之上的特性,能够去除共模信号,而又同时将差分信号放大。仪表放大器的关键参数是共模抑制比,这个性能可以用来衡量差分增益与共模衰减之比。     

精密仪表放大器INA326/327及其应用

INA326/327是TI公司生产的精密仪表放大器,它的内部采用独特的拓扑结构,实现电源正负限输入/输出,非常适用于单电源,低功耗和精密测量的应用场合,文中介绍了INA326/327的内部结构和主要性能指标,同时给出了其典型的应用电路。     

Design and Implementation of Ultralow Current-Mode Amplifier for Biosensor Applications

Recently, along with the booming of research and production of a CMOS integrated biosensing system (IBS), the ultralow current-mode amplifier (ULCA), which serves for the preamplification of biosensor signals, has been in high demand in areas like ultralow biocurrent analysis and detection, deoxyribonucleic acid probing and surveying systems, etc. In this brief, a novel ULCA is presented and implemented in SMIC 0.18- mum CMOS technology by elaborately considering gain, bandwidth, noise, and offset issues. The experimental results show that the proposed ULCA can completely satisfy the specifications of IBS and stably provide the current gain of 19.9 dB, 3-dB bandwidth of 15 kHz, and input range of -0.4 to 0.4 mA, with only 1.5 nA of dc quiescent current. The input-referred offset and the noise current are 96.6 pA and 37.6 pArms, respectively.     

A ± 0.75-V Compact CMOS Class-AB Current-Mode Exponential Variable Gain Amplifier

In this brief, a novel class-AB implementation of a current-mode exponential variable gain amplifier (VGA) is presented. The VGA is based on a novel current amplifier circuit implemented by multicoupled MOS translinear loops operating in strong inversion and saturation. The gain is conveniently configured for performing a pseudo-exponential approximation leading to a very compact design since an extra multiplier is not needed. Moreover the VGA can operate with very low voltage and power efficiency. Measurement results from a fabricated prototype in a 0.5-mum n-well CMOS technology reveal gain control up to 12 dB with errors less than plusmn0.5 dB and power consumption of 375 muW for a supply voltage of plusmn0.75 V.     

A CMOS Low Noise, Chopper Stabilized Low-Dropout Regulator With Current-Mode Feedback Error Amplifier

Low $1/f$ noise, low-dropout (LDO) regulators are becoming critical for the supply regulation of deep-submicron analog baseband and RF system-on-chip designs. A low-noise, high accuracy LDO regulator (LN-LDO) utilizing a chopper stabilized error amplifier is presented. In order to achieve fast response during load transients, a current-mode feedback amplifier (CFA) is designed as a second stage driving the regulation FET. In order to reduce clock feed-through and $1/f$ noise accumulation at the chopping frequency, a first-order digital ${Sigma}{Delta}$ noise-shaper is used for chopping clock spectral spreading. With up to 1 MHz noise-shaped modulation clock, the LN-LDO achieves a noise spectral density of 32 ${hbox{nV}}/{surd}{hbox{Hz}}$ and a PSR of 38 dB at 100 kHz. The proposed LDO is shown to reduce the phase noise of an integrated 32 MHz temperature compensated crystal oscillator (TCXO) at 10 kHz offset by 15 dB. Due to reduced $1/f$ noise requirements, the error amplifier silicon area is reduced by 75%, and the overall regulator area is reduced by 50% with respect to an equivalent noise static regulator. The current-mode feedback second stage buffer reduces regulator settling time by 60% in comparison to an equivalent power consumption voltage mode buffer, achieving 0.6 $mu{hbox{s}}$ settling time for a 25-mA load step. The LN-LDO is designed and fabricated on a 0.25 $mu{hbox{m}}$ CMOS process with five layers of metal, occupying 0.88 ${hbox{mm}}^{2}$.      

低噪声、低失调仪器放大器INA217及其应用

INA217是一种低噪声、低失调的集成仪表放大器。它具有较宽的带宽和增益动态响应。IN A217独特的失调消除电路使其即使在高增益时也能把失调减小到最低范围 ,适用于低频音频信号采集系统的前置放大器、变频放大器、桥式传感器放大器、差动接收器、医疗仪器和仪器仪表等方面。文章介绍了INA217的功能特点、主要参数和几种应用电路     

增益可调射频宽带放大器设计

本放大器由两级构成,3个OPA2695级联组成的固定增益同相放大器构成前级放大器,对输入信号做放大处理;后级增益可调电路由乘法器AD835实现,通过调整单片机DA输出控制总增益,最终实现通频带为0.3MHz～100MHz、增益0dB～+60dB可调的射频宽带放大器.     

Electronically Tunable Current-Mode Universal Filter Employing Only Plus-Type Current-Controlled Conveyors and Grounded Capacitors

A new current-mode current-controlled three-input single-output universal filter, which employs only five plus-type second-generation current-controlled current conveyors (CCCIIs) and two grounded capacitors, is presented in this paper. The proposed configuration provides lowpass, bandpass, highpass, bandstop, and allpass current responses at a high impedance terminal, which enables easy cascadability of the circuit. The filter also offers independent electronic control of the natural frequency ω_o and the quality factor Q through adjusting of the bias current of the CCCII. Derived analytical expressions for the filter parameter deviations due to CCCII nonidealities are also included. PSPICE simulation results are performed to confirm the theoretical analysis.     

A Novel Class AB CMOS Power Amplifier

A novel class AB design is described. To achieve a large output voltage swing and to avoid the offset problems associated with a class AB input stage, the non-linearity is placed between the input and the output stage. Before the output stage the signal is separated in one positive and one negative half, which are then amplified separately.For the first time this topology is used in an integrated CMOS power amplifier. It operates with +/ –2.5 V supplies and can drive more than 4 V_pp into an 8 load.