正交解调器降低RF接收器成本

国际整流器公司(IR)专攻运动控制的iMOTION集成设计平台再添两项新器件,全新I R M C K 2 0 1及IRMCK203数字控制集成电路(IC).     

单周期控制的功率因数校正电路设计

单周期控制是一种大信号、新颖的非线性PWM控制技术,其优点是能够自动消除一个周期内的稳态和瞬态误差,动态响应快,具有结构简单、控制精度高、控制性能不受电源参数变化影响.阐述一了单周期控制的工作原理,并在此基础上设计了以IR1150为控制芯片的200 W功率因数校正电路.实验结果表明.该电路简单可靠,外围元件少,功率因数超过0.98.系统性能优越.     

基于单周期控制专利技术的IR1150型功率因数校正控制电路及其应用

IR1150是一种在宽范围输入线路电压下以连续导电模式(CCM)工作的功率因数校正(PFC)控制IC.IR1150基于IR公司的"单周期控制"(OCC)专有技术,为PFC提供低成本解决方案.文中介绍IR1150的结构、特点和工作原理,给出其典型应用电路.     

简化离线式开关电源的设计

开关电源的使用日益普及,电视机、机顶盒和录像机均采用这种方式供电,移动电话充电器、PDA(个人数字助理),甚至一些电动牙刷都采用开关电源。     

虚拟机和随机调度技术简化无线设计

一种新的无线设计方法使设计师们能将多种基于分组的标准融合到资源受限的手机硬件中.     

基于单周期控制的交互式PFC数字控制技术

分析了单周期功率因数校正(PFC)技术的工作原理,提出了单周期PFC技术的数字控制方案,并将其应用到大功率交互式PFC系统。采用TI公司的TMS320F28035DSP芯片,设计了一套单周期交互式PFC的数字控制系统,对单周期交互式PFC技术的数字控制方案进行了实验验证。实验结果表明了该数字控制方案的可行性。     

Using a structured design analysis to simplify complex in-housecomputer manuals

A three-stage design analysis that can be added to a prewriting strategy to produce a more efficient and portable computer user manual is presented. The three stages are: preliminary analysis, defining who the audience is, what they presently know about the subject, what they need to know, and how they will react to the information presented; needs assessment, a systematic effort that gathers opinions and ideas from a variety of sources regarding performance problems or new systems and technologies; and design for learning, which moves from gathering information to analyzing audience needs, defining learning objectives and designing the manual itself. It is shown that the three-stage process justifies a writer's work by citing specific cost factors and casts the writer in the role of a communication analyst who is capable of finding motivational, environmental, and cost issues in the organization     

Improved control strategy on buck-type PFC converter

In general, a single phase buck-type power factor correction (PFC) converter has a significant problem of the increase in volumetric size and weight, because this type of converter has to employ a smoothing inductor designed for high inductance to reduce the harmonic components included in the line input current. A new control strategy is proposed for a buck-type PFC converter which can greatly reduce the size and weight of its smoothing inductor     

基于氮化镓器件的Boost PFC设计与损耗分析

基于硅(Si)器件的PFC Boost已被广泛研究。由于Si器件特性已经被使用接近极限,基于其的变换器特性也很难再提高。氮化镓(GaN)器件的逐渐普及为变换器性能提高到一个新的等级提供了可能。本文系统介绍一款基于GaN器件的Boost PFC的设计,从主电路设计、效率分析到控制原理。最终选用NCP1654 作为电路控制器并采用GaN HEMT及SiC二极管实现了一款300W 200kHz的PFC,最高理论效率达到98.1%。通过仿真和实验验证了系统设计,展现了宽禁带器件在提升系统效率方面的潜力。     

高集成度环绕声编解码器降低音频系统设计门槛

Cirrus Logic最近推出多款环绕声编解码器.该系列产品将帮助音视频接收器及车载音响系统制造商将多通道环绕声性能整合到自己的入门级和中档产品中.