摩托罗拉公司的光电隔离器

摩托罗拉公司的光电隔离器光电隔离器（亦称光电耦合器，简称光耦）由一个红外发光二极管和一个光检测器构成，主要用于电路的隔离，强电到弱电的转换，尤其是工业场合中的电信号与微处理器可处理的ＴＴＬ电平信号的转换电路。光电隔离器的输入有只对直流电有效的，也有对...     

光电隔离器的工作原理和应用

本文简要介绍了光电隔离器的结构和工作原理,简述了光电隔离器的主要参数和几个应用电路。     

光电隔离器6N137的特性和应用

光电隔离器是电子线路中隔离电压冲击及噪声串扰的优选器件，具有体积小、隔离效果好、价格便宜、便于安装等特点。文中结合Ａ／Ｄ转换电路的实例，以６Ｎ１３７为典型芯片，详细介绍了光电隔离器的性能和使用方法。     

汽车电子

ADI推出系列数字隔离器，Allegro推出汽车级三相MOSFET预驱动器     

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。     

新型电路元件PVI的内部原理及应用

美国国际整流器公司的光电隔离器可认为是一种电流控制浮置恒压源，其输出电流和输入电流成线性关系。是一种具有革命意义的新型元件，通过ＰＶＩ的并联和串接，可大大简化现有ＭＯＳＦＥＴ的高端驱动，浮动电源，线性电源，变换器，光耦合器，信号隔离器，Ｉ－Ｄ接口等种种电路。     

新品展台

ADI公司推出适合高电压工业 应用的多通道数字隔离器 美国模拟器件公司近日发布其适合高电压工业应用的iCoupler专利技术数字隔离器系列的新产品--AD-uM130x/ADuM140x系列3/4通道数字隔离器。新的3通道和4通道iCoupler数字隔离器不需要使用多个分立器件,仅用一颗单芯片就实现了具有突破性的创新性能;与现在普遍使用的光电耦合器相比,其印制电路板(PCB)面积缩     

ADI发布SPI隔离器ADuM315x,集成度更高

正不久前,ADI公司宣布推出专为串行外设接口(SPI)通信系统而优化的新型数字隔离器系列——ADuM315x SPIsolator。该产品以ADI的iCoupler数字隔离器技术为基础。"新的数字隔离器最高支持40MHz SPI时钟速率,比基于竞争光电耦合器或数字隔离器的解决方案快6倍以上,尺寸小80%以上,成本低85%。"ADI接口和iCoupler数字隔离器     

新型光学波导隔离器

像隔离器和环行器这样一类的非互易光学部件,在集成光路中都是重要器件。迄今为止,许多作者提出了主要以磁光效应为理论基础的光学波导隔离器[1-3]。77年,Castera和He-pner利用GGG上的YIG薄膜,通过试验论证了光波导隔离器[4]。本文所介绍的是一种新颖的利用Ti扩散LiNbO_3Z一片中的光电分支波导(EBW)的光学波导隔离器,同时也给出了试验验证结果。实     

什么是光电耦合器？

光电耦合器也称为光电隔离器或光耦合器,有时简称光耦。这是一种以光为耦合媒介,通过光信号的传递来实现输入与输出间电隔离的器件,可在电路或系统之间传输电信号,同时确保这些电路或系统彼此间的电绝缘。     

Digital implementation of a line current shaping algorithm for three phase high power factor boost rectifier without input voltage sensing

In this paper the implementation of a simple yet high performance digital current mode controller that achieves high power factor operation for three phase boost rectifier is described. The indicated objective is achieved without input voltage sensing and without transformation of the control variables into rotating reference frame. The controller uses the concept of resistance emulation for shaping of input current like input voltage in digital implementation. Two decoupled fixed frequency current mode controllers calculate the switching instants for equivalent single phase boost rectifiers. A combined switching strategy is developed in the form of space vectors to simultaneously satisfy the timing requirements of both the current mode controllers in a switching period. Conventional phase locked loop (PLL) is not required as converter switching is self-synchronized with the input voltage. Analytical formula is derived to obtain the steady state stability condition of the converter. A linear, low frequency, small signal model of the three phase boost rectifier is developed and verified by measurement of the voltage control transfer function. In implementation Texas Instruments's DSP TMS320F240F is used as the digital controller. The algorithm is tested on a 10-kW, 700-V dc, three phase boost rectifier.     

Digitally controlled high power switch-mode rectifier

High power switch-mode rectifiers offer advantages over conventionally used line-commutated thyristor rectifiers in terms of size and cost. This paper describes operation of the high power switch-mode rectifier based on an original control strategy which is digitally implemented. The rectifier is operated in a constant output current mode. The control strategy provides a fast transient response to disturbances and achieves equal current sharing between the buck converter modules which are paralleled within the switch-mode rectifier. Equal current sharing is maintained in steady-state as well as in transient operation. The paper demonstrates that the transient response to load disturbances achievable with the proposed control strategy is superior to the response obtained with the conventional control strategy in terms of the output current overshoot and the settling time. The control algorithm is digitally implemented on a DSP/FPGA based digital control platform and its performance is verified on a 2 kW scaled-down experimental setup of the switch-mode rectifier.     

开关电源数字控制器设计方法的比较

本文从带宽和相角裕度、突加负载时的超调量非线性负载时的输出电压谐波畸变率三个方面，对几种常用的开关电源数字控制器设计方法进行了系统的分析和比较，并给出了仿真结果，最后得出了有用的结论。     

一种数字存储组合式PWM调制方案

提出一种基于数字存储模式的PWM调制方案，讨论其非对称规则采样原理,给出宜于在线运算的简便算法，该方案采用了以EPROM为可编程定时器，并带有锁相同步功能的脉宽调制器的数字化实现方法，高开关频率基本固定，调制比与相位、频率可以独立控制，特别适用于PWM可逆整流器。     

A current mode feed-forward gain control system for a 0.8 V CMOS hearing aid

A current mode feed-forward gain control（CMFGC）technique is presented,which is applied in the front-end system of a hearing aid chip.Compared with conventional automatic gain control（AGC）,CMFGC significantly improves the total harmonic distortion（THD）by digital gain control.To attain the digital gain control codes according to the extremely weak output signal from the microphone,a rectifier and a state controller implemented in current mode are proposed.A prototype chip has been designed based on a 0.13μm standard CMOS process.The measurement results show that the supply voltage can be as low as 0.6 V.And with the 0.8 V supply voltage,the THD is improved and below 0.06%（-64 dB）at the output level of 500 mV_p-p,yet the power consumption is limited to 40μW.In addition,the input referred noise is only 4μV_rmsand the maximum gain is maintained at 33 dB.     

A Voltage-sensorless control method to balance the input currents of a three-wire boost rectifier under unbalanced input Voltages condition

This paper proposes a control method that can balance the input currents of the three-phase three-wire boost rectifier under unbalanced input voltage condition. The control objective is to operate the rectifier in the high-power-factor mode under balanced input voltage condition but to give overriding priority to the current balance function in case of unbalance in the input voltage. The control structure has been divided into two major functional blocks. The inner loop current-mode controller implements resistor emulation to achieve high-power-factor operation on each of the two orthogonal axes of the stationary reference frame. The outer control loop performs magnitude scaling and phase-shifting operations on current of one of the axes to make it balanced with the current on the other axis. The coefficients of scaling and shifting functions are determined by two closed-loop proportional-integral (PI) controllers that impose the conditions of input current balance as PI references. The control algorithm is simple and high performing. It does not require input voltage sensing and transformation of the control variables into a rotating reference frame. The simulation results on a MATLAB-SIMULINK platform validate the proposed control strategy. In implementation Texas Instrument's digital signal processor TMS320F240F is used as the digital controller. The control algorithm for high-power-factor operation is tested on a prototype boost rectifier under nominal and unbalanced input voltage conditions.     

Modeling and analysis of a digitally controlled high power switch-mode rectifier

A recently proposed high power switch-mode rectifier topology offers advantages over the conventional line-commutated thyristor rectifiers in terms of size and cost. This paper presents modeling and analysis of the high power switch-mode rectifier configuration, operated under a newly developed digital control strategy. The developed strategy provides a fast transient response to disturbances and achieves equal current sharing between the buck converter modules which are paralleled within the switch-mode rectifier. A continuous-time state-space model of the switch-mode rectifier and analyses of both the steady-state and the transient operation modes of the digitally controlled rectifier are presented. The continuous-time model is used as a basis for time-domain simulations of the rectifier's behavior in the MATLAB/Simulink environment. The validity of the presented model is demonstrated based on comparison between the simulation results and the corresponding experimental results. The experimental results are obtained from a 2-kW scaled-down laboratory setup of the rectifier. The stability of the digitally controlled rectifier system is also examined based on an overall small-signal sampled-data model of the rectifier system including the controls.     

三相PWM整流器电压空间矢量控制的实现

提出了一种便于数字实现的三相PWM整流器电压空间矢量的控制算法，该算法采用输入电压空间矢量定向，根据参考电压矢量直接计算空间电压矢量的位置和作用时间；利用DSP（数字处理器）实现了三相PWM整流器全数字化控制，并得出了最终实验结果。     

A predictive instantaneous-current PWM controlled rectifier withAC-side harmonic current reduction

A new single-phase bridge rectifier controlled by a predictive instantaneous-current PWM control scheme for reducing AC-side harmonic currents and improving power factor is proposed. The rectifier can operate at the unity displacement power factor and has fast response to an input signal as a current reference. The effect of the DC-side voltage ripples is taken into account. The paper describes three digital control schemes for such rectifiers and presents experimental and simulation studies on steady-state and dynamic performances of the rectifier. The effectiveness of the control schemes is confirmed by experiments and simulations. The proposed rectifier can be used for applications such as UPS systems and static VAr compensators     

DMA42—48／12.5型整流模块简介

DMA42－48／12.5型整流模块是武汉洲际集团公司近斯推出的一种模块。它采用不连续导电模式高功率因数校正和高频开关调制技术,使模块体积小、重量轻、功率因数高、输入电压范围宽。同时,它与监控单元之间采用数字方式进行数据通信,工作可靠性更高。本文简要介绍其工作原理及主要技术指标。