LCD TV开关电源解决方案

随着电源能效规范标准逐渐提高,LCD TV开关电源也需要不断提升能效.为此,提出了从PFC预调节器、主DC/DC级到待机转换器的解决方案.详细地说明了基于NCP1654的PFC预调节器解决方案、基于ICE2QS02G的准谐振反激式主DC/DC级解决方案以及基于ICE3BR4765J的反激式待机转换器解决方案.系统性能的测评结果说明解决方案是合理的.     

新型迷你成像器能够读取微小代码

Power Integrations公司推出TOPSwitch-HX系列AC/DC功率转换器,该转换器集成了700V的功率MOSFET、多模式控制器和监控电路,采用了EcoSmart节能技术,具有出色的待机功耗并可在整个负载范围内实现高效率,可省掉某些应用中使用的独立式待机电源.     

TOPSwitch-HX在整个负载范围内实现高效率

Power Integrations公司推出TOPSwitch-HX系列AC/DC功率转换器,该转换器集成了700V的功率MOSFET、多模式控制器和监控电路,采用了EcoSmart节能技术,具有出色的待机功耗并可在整个负载范围内实现高效率,可省掉某些应用中使用的独立式待机电源.     

低功耗电流模式PWM控制功率开关芯片BL9705应用

BL9705芯片可以应用于多种电源控制的领域，主要是电子设备的AC／DC反激式变换器中，包括电池充电器、电源适配器、机顶盒电源、开放式开关电源。BL9705具有高集成度、低待机功耗、高性价比等优点。跳周期模式极大地降低了待机功耗，帮助电子设备的设计者们更加容易地满足功耗要求。     

德州仪器电源管理IC为AC/DC电源实现业界最高效率与最低待机功耗

正日前,德州仪器(TI)宣布推出两款可为5至100W AC/DC电源实现最高能源效率与最低待机功耗的反激式电源解决方案。该UCC28910 700V反激式转换开关与UCC28630高功率绿色环保模式控制器进一步壮大了TI领先反激式控制器的产品阵营,涵盖完整电源范围的AC/DC适配器与电源,可充分满足个人电子产品、打印机、大型家用电器以及智能仪表的应用需求。     

系统微功耗设计需考虑的因素

系统的功耗设计是相对而言的,不仅仅用电池供电的设备需做功耗,使用交流供电的设备亦有“微功耗”的需求。目前限制开发人员的并非是控制器这单一技术,周边设备有时消耗的无用功率,要较控制器多得多。以一个AC－DC电源为例,在单片机空闲的情况下,单片机的功率不会超出数个mW,但是即便是普通绿色电源,也允许AC－DC的功率在1W左右。这种待机状态是在应用领域广泛存在的,如带遥控装置的家用电器、计算机的ATX电源、激光打印机等等。待机系统功耗占全球消耗的比重远远超出我们的想象,所以欧洲一些国家规定出更低一些的待机电力消…     

德州仪器推出7款SIMPLE SWITCHER稳压器

正德州仪器推出7款SIMPLE SWITCHER稳压器,不仅可简化宽泛VIN同步电源设计,而且还有助于工程师创建符合电磁干扰(EMI)标准的高能效产品。简单易用LM43600/1/2/3与LM46000/1/2DC/DC转换器不但支持高达60V的输入电压,在不够完善的系统中依旧表现出了良好的可靠性,同时还支持27毫安的待机电流,可最大限度降低轻负载功耗。其独有的同步功率级架     

极低功耗单片AC/DC电源管理IC的设计

为了进一步降低AC/DC电源管理IC在正常工作和待机工作时的功耗,本文从分析整个系统的功耗出发,分别设计出相应的电路,有针对性的降低每一部分功耗,从而降低整个系统的功耗,提高系统的效率.整个系统实现控制电路和大功率管的单片集成,采用QR、PFM和BURST三种工作模式.在CSMC 1μm 700VBCD工艺下完成了整个系统的设计和仿真验证.仿真结果表明,该电源管理IC达到了预期的性能要求.     

一种采用线补偿技术的原边反馈AC/DC控制器

基于1μm 40V BCD工艺,使用Cadence软件对原边反馈AC/DC控制器进行仿真和分析。线补偿技术可以使原边反馈AC/DC电路获得很好的负载调整率,抵消电感上所消耗的电压和整流二极管上的压降,使输出达到的最佳值。在输入加220 V交流电压时,输出结果最大值为5.09 V,最小值为5 V,最大负载调整率为9.609%。     

元器件与组件

超低内阻、适用通信及工业电源的150V MOSFET AON6250是一款150V MOSFET,为众多追求极致效率的设备提供了解决方案。AON6250适用于通信及工业电源DC/DC转换器原边开关、AC/DC及DC/DC转换器副边同步整流,太阳能微逆变器,以及通信系统中的负载点模块(POL)。采用先进的AlphaMOS技术,AON6250实现了领先的低导通内阻和高速开关性能。该产品与上一代产品相     

高效单级变换式LED驱动电源设计

无论民用或商用领域,功率100 W以下的交流电源都有着巨大的应用需求。由于要兼顾输入谐波电流、功率因数、系统能效等问题,采用临界模式（boundary mode）的AC/DC单级反激式的电源拓扑成为非常完美的小功率直流电源解决方案。它具有高的转换效率,在高端小电源供应器中的应用越来越广泛,特别是在LED照明驱动方面极具优势。文章主要阐释小功率（≤100 W）单级AC/DC转换器的原理,分析其正弦调制原理及获得高功率因数、高能效的原因,并探讨了转换器的功能和优点,最后设计了一个采用仙童FAN6961芯片控制的48 V输出75 W的LED驱动电源,实验验证和批量生产证明本方案设计合理、产品性能稳定、可靠性好,能够有效提高能效、功率因数,避免建筑物内高次谐波电流造成的电源环境污染。     

A New Topology With High Efficiency Throughout All Load Range for Photovoltaic PCS

In this paper, a new topology is proposed that can significantly reduce the converter rated power and increase the efficiency of total photovoltaic (PV) system. Since the output voltage of PV module has very wide operating range, in general, the DC/DC converter is used to produce constant high-DC-link voltage for DC/AC inverter. According to the analysis of the proposed topology, only 20% of total PV system power is processed by the DC/DC power conversion stage. The DC/DC power conversion stage used in proposed topology has flat efficiency curve throughout all load range and very high efficiency characteristics. In the proposed topology, because the converter efficiency curve is almost flat throughout all load range, the total system efficiency at light load is dramatically improved. The proposed topology is implemented for 250-kW power conditioning system. This system has only three DC/DC power conversion stage with 24-kW rated power. It is only one-third of total system power. The experimental results show that the proposed topology has good performance.     

Voltage-source charge-pump power-factor-correction AC/DC converters

Voltage-source charge-pump power-factor-correction (VS-CPPFC) AC/DC power converters are proposed in this paper. The PFC converter using the CP concept is first derived. The unity power factor condition is derived and analyzed. The clamping technique is used to satisfy the unity power factor condition. Based on the steady-state analysis, design considerations for the CPPFC stage are discussed. A family of VS-CPPFC topologies is also presented. The proposed VS-CPPFC AC/DC power converter was implemented and tested. The experimental results show that 83.5% efficiency and 0.996 power factor can be achieved for a half-bridge CPPFC AC/DC converter with 250-W and 12-V output,     

大功率电弧加热器电源的设计研究

研究了63MW等级的大功率电弧加热器交直流电源的主电路设计和控制策略。提出了一种相移叠桥组合晶闸管整流主电路结构,使得该电源输出直流电压从1kV到21kV的不同工况时,其输入端的功率因数不小于0.9,且高功率时THD小于5%。根据主电路相移叠桥结构的特点,提出了一种非线性反馈控制器和前馈控制器相结合的复合稳流控制策略,稳流精度能够达到0.1%。实验结果表明,相移叠桥组合晶闸管主电路结构达到了电源电能质量设计指标;采用复合稳流控制策略后,稳流精度不仅能够达到设计指标,而且可以去掉主电路中的稳流电阻,从而减小了电源系统1.8MW的电阻热耗。     

On lossless switched-capacitor power converters

This paper addresses the design of efficient switched-capacitor power converters. The discussion starts with a review of the fundamental limitation of switched-capacitor circuits which shows that the topology of such circuits and the “forced” step changes of capacitor voltages are the inherent attributes of power loss. Although the argument follows from a rather trivial result from basic circuit theory, it addresses an important issue on the maximum efficiency achievable in a switched-capacitor power converter circuit. Based on the observed topological constraint of switched-capacitor power converter circuits, the simplest lossless topology for AC/DC power conversion is deduced. Also discussed is a simple version of lossless topology that achieves isolation between the source and the load. Finally, an experimental AC/DC switched-capacitor power converter, based on the proposed idea, is presented which demonstrates an improved efficiency over other existing switched-capacitor power converters. The proposed AC/DC power converter contains no inductors and thus is suitable for custom IC implementation for very low power applications     

双H桥双峰双向脉冲电镀电源设计与仿真

为了使脉冲电镀电源输出频率可调,电压可调,正向脉冲开启时间宽度和负向脉冲开启时间宽度可调的双峰双脉冲。特此提出了一种绿色可靠、节能高效的新设计方案,第一个H桥采用ZVZCS PWM DC/DC变换器对输入的直流电压进行降压,变成高频交流脉冲电压,然后经过高频变压器的隔离和耦合,再通过桥式整流滤波得到稳定的直流电压,最后经过第二个H桥进行切换,得到任意频率,任意占空比的双峰双向脉冲。实验证明应用该方案能降低开关管的开关损耗,降低元器件的要求,能将电源的效率提高到90%以上,同时由于此电源具有脉冲换向功能,在电镀时,大大增加了贵金属的利用效率。     

An Improved Single Stage Phase Shifted Control Based AC–DC PFC Converter for Wireless Applications

Recently, many researchers has more attention in a single stage AC to DC converter features and DC to DC regulator are extensively used into low power applications. When compared with the two stage conventional method over the Single stage converter has a simple design and utilize only less components. Therefore, this task has been used in this paper as a prposed work of AC–DC single stage converters combine a converter front end with DC–DC back end converter. This proposed work has been improved single stage power factor correction (PFC) converter based on phase-shifted controller for wireless Power applications. The proposed technique employed to develop the improved converter for task of an extensive series of voltage outputs with rippleless outcomes in low frequency, that shows the high essential in battery application and the PFC duty ratio restriction is eradicated. Similarly, DC–DC stage operation are designed in a related way of conventional full bridge phase shifted converter. Accordingly, the proposed technique of improved converter of this paper will achieves better efficiency compared with other conventional techniques and it has been prove more efficient for many Industrial applications, it has been discussed in result section clearly. The experimental results of proposed improved converter proves that it is potential to extend high power single stage converter with good power factor, conversion characteristics and efficiency.

     

A low-cost CMOS dual-mode AC/DC data converter for signal measuring technique

A low-cost CMOS dual-mode AC/DC data converter for signal measuring technique is newly proposed. Instead of traditional full wave rectification, the realized synchronous rectification circuit is more attractive due to the easier integration and lower cost. In this paper, the design strategies of implementing the signal processing of AC and DC modes in the integrated circuit are discussed completely. Proven through SIMULINK in system level and SPICE simulations in circuit level, simulation results show that the proposed dual-mode AC/DC data converter achieves 8-bit resolution in DC mode and 7-bit resolution in AC mode. Measurement results have successfully verified the correct functions and performance of the proposed data converter and confirmed it for AC/DC signal measuring technique. The area of this chip is 710 × 630 μm² and the measured power consumption is 5.1 mW. The proposed dual-mode AC/DC data converter is suitable for the system of analog and mixed-signal boundary scan.     

An alternative to supply DC voltages with high power factor

AC/DC is one of the most common power conversions in power electronics, DC loads should be fed with a stable and a tight regulated voltage. At the same time, the AC/DC converter should comply with low-frequency harmonic regulation. The classical two-stage AC/DC converters achieve these two objectives, although the overall efficiency is low because the power is processed twice. An alternative solution is presented in this paper. It is based on the division of the input power in two parts, one of them processed only once and keeping a unity power factor. This strategy improves the efficiency and reduces the size of the converter without any complex control scheme. This proposal can be implemented with a great variety of well-known topologies. The experimental results show that this solution is a good tradeoff between efficiency and size     

基于电驱动钻机的交流电子负载的研究

基于现代电力电子技术,深入研究能量回馈式的交流电子负载的主电路结构和控制策略。主电路采用AC／DC／AC拓扑,并选用电压型PWM整流器构成其输入、输出变流器。提出了一种基于DSP的交流电子负载的控制策略。