Astrodyne开架式隔离DC／DC转换器

Astrodyne扩展了其开架式隔离5W，7W和10W DC／DC转换器生产线，符合EN60950和UL60950-1SELV安全标准。ASDH系列包含48个模型，4：1的输入范围：直流9V到直流36V，直流18V到直流75V，从直流3V到直流15V的单向及双向输出。该产品的特点是开架式结构，具有集成的鳍状散热器，工作温度范围从-25℃到＋71℃。     

嵌入式POL DC/DC转换器设计

大多数嵌入式系统都是通过48V背板供电的。这个电压通常要降为更低的12V或5V中间电压,以向系统内的电路板供电。然而,在这些电路板上,大多数电路都要求供电电压范围在0.8V～3.3V,电流范围为几十mA至几十A。因此,需要负载点(POL)DC/DC转换器对12V或5V降压,以获得所需的电压和电流值。     

数字控制隔离DC／DC转换器BMR453

BMR453系列四分之一砖DC—DC转换器集成了一个数字控制平台,这一方法承诺释放了真正资源以增加功率密度。器件具有96％的效率,提供400W的输入功率,或高达33A及±2％的精度。输入电压范围为36～75V,输入电压在8．5～13．5V之间可变。目标应用包括必须使用电信输入电压并具有备用电池或－48V和－60V额定输入电压的系统。     

CN-A系列DC／DC转换器

TDK-Lambda扩展DC／DC转换器系列,推出具有60VDC-160VDC宽输入范围的新CN-A系列,广泛用于铁路应用中。标称输出电压为5V-24V（可调±10％）,额定功率达100W。这些宽输入范围、全调节和隔离电源提供标准1／4砖占位面积的优良性能。     

基于LTC3789的DC/DC变换器设计

为将宽输入范围直流电压变换成稳定直流电压输出,以控制器LTC3789为核心,高速、高频、低损耗MOSFET器件为控制开关,采用恒定频率的电流控制模式,设计了一款能够实现宽范围输入电压同步、无缝、高效的升压-降压DC/DC变换电路,并进行了物理实验验证。实验结果表明,所设计的以LTC3789为控制核心的电路能够实现6-30V直流输入,12.8V稳定直流输出的DC/DC变换,并且电路工作稳定、可靠。     

轻松选择DC/DC变换器

分布式供电体制(distributed-power architectures,DPA)的盛行,极大地促进了集成DC/DC变换器的发展。本文主要讲述了DC/DC变换器在评测、对比和选型时的需要注意的问题,以协助DPA设计人员在市场上挑选出合适的产品。功率、输入和输出首先要考虑的是输入电压、额定功率以及输出电压的大小和种类。根据额定功率的大小,DC/DC变换器通常可分为超低功率(1W以下)、小功率(1～9W)、中功率(10～150W)和大功率(150W以上)等类别。大多数变换器的输入电压是12V或24V,对于那些要求输入电压可变或者输入电压不标准的场合,可以选用具有宽电源输…     

MAX641/642/643升压型DC/DC变换器

1AX641/642/643简介MAX641/642/643是美国MAXIM公司生产的升压型DC -DC变换器 ,它具有较宽的输入/输出范围 ,其中输入电压范围为3～12V ,输出电压范围为5～50V ;工作温度范围为 -55～125℃ ;在输出电压方面 ,该系列产品具有5、12、15V等多种输出可供用户任意选择。MAX641/642/643系列DC -DC的功耗电流小于135μA ,而同时其转换效率却高达80 %。当MAX641/642/643单独构成DC/DC变换器时 ,其输出功率为5mW ,如果外加MOSFET功率开关管 ,其输出功率可扩展到10W。MAX641/642/643具有DIP8和SO8两种封装形式 ,其内部原理框图如…     

今天的绿色POL DC/DC转换器设菅需要高效率和低IQ

大多数嵌入式系统都是由48V背板供电的。这个电压通常要降至较低的24V、12V或5V的中间总线电压,以向系统内的电路板支架供电。然而,这些电路板上的大多数分支电路或集成电路要求在低于1～3．3V的电压范围内工作,电流范围为数十mA至数十A。因此,需要负载点（POL）DC／DC转换器将24V、12V或5V电压轨降至这些分支电路或集成电路所需的电压和电流值。     

新型集成电路简化嵌入式POL DC/DC转换器设计

1、背景大多数嵌入式系统都是由48V背板供电的。这个电压通常要降至较低的12V或5V中间电压,以向系统内的电路板支架供电。然而,这些电路板上的大多数分支电路或集成电路所要求的供电电压范围为0.8V至3.3V,供电电流范围为数十毫安至数十安培。结果,需要负载点(POL)DC/DC转换器将12V或5V电压降低至这些分支电路或集成电路所需的电压和电流值。     

RECOM率先推出20W～50W功率范围的全新的DC/DC转换器系列

日前,RECOM在业界率先推出20W～50W功率范围的全新的DC/DC转换器系列。PowerlinePlus系列是首批采用RECOM创新ICE技术转换器方面卓越性创新的模块,该技术是多种技术的组合,     

A current-tripler dc/dc converter

This paper proposes a novel zero-voltage-switching (ZVS) current-tripler dc/dc converter. Compared to the conventional phase-shifted ZVS full-bridge dc/dc converter with current-doubler rectifier, the proposed current-tripler dc/dc converter reduces the synchronous rectifier (SR) conduction loss as well as the transformer winding loss. Furthermore, the proposed transformer structure is very compact, and thus the power density of the converter could be greatly increased. Analysis and experimental results show that the proposed topology offers great advantages when the converter output current goes higher and the voltage goes lower, as demanded by future microprocessors and telecommunications systems. A 48-V/1.0-V, 100-A, 300-kHz prototype is implemented, and the experimental results show that it can achieve 87% efficiency at full load.     

DC／DC变换器中的噪声管理

零电流开关器件产生的谐波和寄生噪声较少,适合于噪声敏感型用途     

产生双极性输出的无变压器DC／DC变换器

要从单个正极性输入产生双极性(正和负)输出的常见方法是采用变压器.虽然这种设计比较简单,但变压器本身会带来体积问题.把一个变压器装入一台要求减小电路占用面积和高度的设备中,这是具有挑战性的.图1所示电路可以从由3V～10V输入产生±5V输出,适用于没有地方安装变压器的设备.该电路所用的一种结构,能在DC/DC变换器处于关机模式时切断两个输出,这样就使处于关机(待机)模式时的静态电流很小.     

使DC/DC变换器限流特性线性化的热敏电阻器网络

最近推出的各种集成式降压DC/DC变换器均已采取对外接低侧MOSFET同步整流器的电压降采样的方法,无需高侧电流检测电阻器。这种拓扑节省了检测电阻器的成本和印制电路板的空间,也适当提高了电路效率。但是,MOSFET的导通电阻与温度有很大的相关性,它决定了限流大     

A dc transformer

Although conventional transformers are ac, a device that may be termed a dc transformer has been constructed by using superconductors. To provide an understanding of how such a transformer would operate, some of the properties of type I and type II superconductors are reviewed. Since the dc transformer under discussion is constructed from thin superconducting films, the main emphasis is on these structures; the concept of flux motion is also explained. The result of the work described is a device in which a direct current or voltage can be transformed, and in which it is possible to extract power from the secondary circuit.     

在300mV供电电压下工作的JFET DC／DC转换器

使用JFET的自偏置特性可以建立一个DC/DC转换器,它能用太阳能电池、热电偶和单级燃料电池等电源工作,这些电源电压都低于600 mV,有的甚至低至300 mV。     

新型引脚技术提升了DC/DC转换器的性能和可靠性

DC/DC转换器制造商C&DTechnologies公司(位于美国亚利桑那州图森)开发的PositionPerfect引脚技术消除了元件在组装时发生移动的可能性,从而使无引线SMTDC/DC转换器的机械安装整体性和精确性均有所提高。与传统技术相比,此项技术还能够使转换器引脚提供更高的电流,从而确保将满载的额定电流输送至主PC电路板上。该技术运用了SMT互连,这种SMT互连采用了由高速自动模锻工艺固定在转换器上的独特铜柱。在模锻处理之后进行的修剪形成了极端平整的表面,从而确保了引脚的共面误差小于0.004英寸,并且消除了元件的移动。将引脚固定在转换器…     

Submarine dc cables

Since 1900 most of our power has been supplied by alternating current, but the high-voltage electron tubes and the rectifying equipment developed during the last decade have revived our interest in direct current. Because geographical factors have made most of our present-day dc cables submarine, we find that we are beset by the same problems that were involved with their historical antecedents? transatlantic telegraph, and later telephone, cables. Mechanical problems arise because of the complex structure of a cable, and because of all of the stresses to which it is subjected. There is also the problem of electrical stress. A comparison of the various types of cable shows that rugged, lightweight equipment is desirable, and that taped insulation insures reliability.     

A prognostic method for predicting failure of dc/dc converter

The failure of dc/dc converters can directly result in electronic systems working unconventionally or significant downtime. To pre-determine time to failure and generate substantial safety and cost benefits, it is necessary to assess the extent of deviation of dc/dc converters from its expected state of health in real time and predict time to failure in advance. This paper presents a novel prognostic method for predicting the time to failure of dc/dc converters. The process involves identifying precursor parameters, determining prognostic of failure, and determining a criterion for predicting time to failure. The output voltage is used as a precursor parameter and directly monitored when the converter with a given load periodically operates at different temperature stresses. The phenomenon that the differences of output voltages collected at different temperature stresses begin to increase with a large (or small) fluctuation is detected in collected output voltages. This phenomenon is identified as a prognostic of failure. A percentage of the initial difference is used as the criterion for predicting time to failure. A case study is given to illustrate the procedure that how to monitor output voltages, detect prognostic and predict time to failure. The results show the health state could be assessed in real time and the time to failure could be predicted in advance. Furthermore, the deviation of the predicted time to failure from the actual time to failure could meet the demand of a considered acceptable range in engineering practice.