仪表放大器及应用

仪表放大器是一种高增益、直流耦合放大器，它具有差分输入、单端输出、高输入阻抗和高共模抑制比等特点。差分放大器和仪表放大器所采用的基础部件(运算放大器)基本相同，它们在性能上与标准运算放大器有很大的不同。标准运算放大器是单端器件，其传输函数主要由反馈网络决定；而差分放大     

一种新型隔离放大器的研制

简要介绍了BB-3656隔离放大器的电路原理,详细论述了替代该型号放大器的一种新型隔离放大器的设计要点和设计方案,并给出了仿真和测试结果。     

运算放大器共模抑制化的测量方法

共模抑制比(CMRR)是指差分放大器对同时加到两个输入端上的共模信号的抑制能力。更确切地说，CMRR是产生特定输出所需输入的共模电压与产生同样输出所需输入的差分电压的比值。同时，CMRR还等于放大器开环共模增益与开环差模增益的比值。本文下面所描述的测试方法可快速获得CMRR与频率关系的曲线图，而且其测量结果在DC到几十兆赫兹频率范围内都无误差，并可重复测量。     

一种自旋阀GMR隔离放大器设计

为了解决传统光电隔离、电容隔离和变压器隔离存在的线性度及频率特性等问题,设计了一种自旋阀巨磁阻（GMR）隔离放大器,具有灵敏度高、线性度好及结构简单等特点,且可以与硅等半导体电路集成。基于CSMC 0.5μm混合信号工艺,采用Tanner软件对电路进行编辑、仿真与验证。隔离器前端电路可将0～5 V的输入电压转换为1.4～10 mA电流,后端接收电路在增益为1时的共模抑制比为73 dB,增益可调节范围为1～200,工作带宽大于100 kHz,能满足恶劣环境条件下应用的各项指标要求。     

新型光耦合集成隔离放大器3650和3652

3650和3652是美国B -B公司出品的新型高性能光耦合集成隔离放大器 ,它们尺寸小、价格低、带宽宽、性能可靠。文中介绍了3650和3652的工作原理和应用设计 ,并给出了几种应用电路的连接方法。     

带隔离电源的线性隔离放大器

带隔离电源的线性隔离放大器武汉工学院张菊秀干扰对计算机测控系统的影响，几乎是每个开发者都曾遇到过的问题。外界的各种干扰信号大多是以共模信号的形式通过信号线、电源、地线串人系统，影响其正常工作。因此要提高系统抗干扰的能力，必须解决防止干扰信号进人系统的...     

新一代三端隔离放大器的外形结构及应用

详细介绍三端隔离放大器的外形结构、使用方法和具体应用。     

不平衡输入高级放大器

附图所示的放大器使用了SSM-2015的增益可调节．能接收从-27．5dBu～0dBu的带有30dB家用磁头(headroom)的标称音频信号。输入端有30Vp—P值的共模电压公差。在1000Hz时的噪声抑制大于100dB，而eIN(等效输入噪声)小于-124dBu。     

智能化传感器中应用仪表放大器的电路设计

在智能化传感器系统中广泛采用仪表放大器构成信号的放大处理电路。放大差分信号的仪表放大器在实际应用中,要考虑输入共模电压范围、增益的选择、滤波、共模频率、输入电流回路设计等问题,以及选择信号的输入方式。针对这些问题,本文进行了较为详尽的讨论。     

高精度数据采集放大器AD522及其应用

AD522是AD公司推出的高精度数据采集放大器,利用它可在恶劣工作环境下获得高精度数据。文中介绍了其主要特点,给出了AD522的典型应用电路,并对AD522在特殊应用情况下的漂移、增益、共模拟制比的调整方法作了说明,最后还指出了AD522的误差形成原因及调整方法。     

磁饱和放大器及其应用

本文通过介绍磁饱和放大器的原理以及ＰＣ电源和ＭＡ电源在各种负载下的比较试验来说明一种最新磁饱和放大器及其在开关电源中的应用情况。它彻底解决了开关电源多路输出大电流、高精度的稳压问题，为工业控制计算机系统，特别是１６位系统的高精度电源开发奠定了基础。     

线性光电隔离放大器SLC800及其应用

隔离放大器广泛应用于通信、工业控制、仪器仪表及医疗电子设备中。线性光电隔离器SLC800可以在输出信号与输入伺服反馈信号之间提供良好的匹配。本介绍线性光电隔离器SLC800及其应用方法。     

高性能集成运放的教学与应用

论述了高性能集成运放教学的必要性、必要的知识铺垫和主要知识点。列举了三种不同高性能运放的应用实例。     

低噪声可变增益放大器的性能及应用

AD603是美国AD公司推出的主要应用于射频和中频自动增益控制系统的一种低噪声、压控增益放大器。详细介绍AD603的工作原理、噪声特性、模式选择、增益控制方法，提出几个AD603级联使用的方法，最后介绍低噪声自动增益控制放大器的设计原理及实际应用电路。     

单通道分组语音处理器AC48801C-C 的介绍和应用

AC48801C-C是以色列AudioCodes公司推出的单通道分组语音处理芯片，主要用于语音带的信号处理，支持具有长话质量、低比特率的语音编解码标准和兼容的T．38传真业务标准。本文介绍了AC48801C-C的特点和接口，分析了芯片的软件模块和工作模式。     

Performance Characteristics of 4-Port Stripline Circulators (Short Papers)

Impedance matrix formulation is applied to the 4-port stripline circulator to determine the optimum performance. The space harmonics generated in the ferrite disk are determined. The distribution of the electric field and the power densities across the ferrite disk are clearly presented. Using an inner dielectric provides more flexibility in the design,     

Isolation Amplifier Energized by Ultrasound

A power supply energized by ultrasound has been developed and investigated. The supply can be used in medical applications where a high isolation from earth is essential, for example in the protection of a patient from the hazards of electric shock caused by medical instrumentation. The ultrasound energy is generated by a transmitting piezoelectric crystal (transducer) and sent to a receiving transducer via a glass rod 20 mm long. At the receiving transducer the acoustic energy is converted back to electric energy. The power transmission has been measured at different resonances of the glass rod-transducer combination. The radial mode resonance of the transducer seems to give the largest power transfer and the highest efficiency.     

Theory of Operation of a 3-Port Y-Junction Ferrite Circulator

An analysis is made of the operation of a 3 port Y-junction ferrite circulator wherein it is assumed that the ferrite cylinder can support the propagation of a bound surface wave. The incident wave guided by the air-dielectric interface of the ferrite cylinder is taken to be linearly polarized parallel to the ferrite axis and after incidence on the cylinder is assumed to divide and propagate in opposite directions about the cylinder as two linearly polarized signals. By appropriate selection of ferrite cylinder diameter, permeability, magnetizing field and saturation magnetization, constructive and destructive interference of the RF components are shown to occur at the two output ports. The conditions for reinforcement and null at the outputs are discussed and compared with published experimental data. It is possible to predict the occurrence of ferrite circulator diplexing reported by Brown and Clark although good quantitative comparison is lacking. The theoretical dependence of ferrite diameter upon free space wavelength is computed and compares satisfactorily with recorded experimental data. The experimental observations that greater circulator bandwidths are achievable when below resonance magnetizing fields are employed are shown to have a theoretical basis. In addition, interrelationships among the designed variables: saturation magnetization, applied magnetic field, ferrite resonance linewidth and circulator insertion loss are noted in the theoretical results.     

A Study of Nonlinearities and Intermodulation Characteristics of 3-Port Distributed Circulators

Results of a study of nonlinearities and intermodulation characteristics of 3-port distributed circulators are presented. Based on a rigorous theoretical analysis of the third-order nonlinearity in ferrites, analytical results are derived for the field strength and the power level of the intermodulation signal. These explicit results are applicable to high-power distributed circulators operating in VHF, UHF, and microwave frequencies. Measured intermodulation characteristics of an experimental distributed VHF high-power circulator are also presented.