基于Sepic和Flyback混合拓扑的辅助电源设计

分析了Sepic和Flyback拓扑结构,根据DC/DC模块电源对辅助电源的需求,提出了Sepic和Flyback混合拓扑的辅助电源,能够输出多路不同幅值电压,并且可以实现各路输出电压之间的隔离。利用状态空间平均法建立了Sepic拓扑的小信号模型,设计了电压和电流双环控制的补偿器,并用Matlab仿真软件进行了分析。该辅助电源应用于一款非隔离的宽范围输入且输出可调的DC/DC模块电源,实现了三路互相隔离的12 V输出电压,一路非隔离的6 V输出电压,输出电压波形稳定,能够满足隔离悬浮供电,也能满足不同芯片对电压范围的要求。     

基于电池供电的双路隔离反激开关电源设计

针对便携式医疗康复设备领域中电池供电、高隔离度和高电压输出的要求,设计了一款新型低输入电压供电、双路高压输出隔离的开关电源。该设计采用锂电池供电,采用基于占空比＜50%的电流型脉宽调制控制芯片UC3845的反激拓扑结构和光耦反馈网络电路,实现双路隔离正负高压电源输出。电源输入电压为10～14 V,输出电压为双通道+35/-35 V隔离,功率为14 W,效率是75%,电源模块面积为65 mm×40 mm。仿真与实际测试结果表明,该电源可实现正负高压电源隔离输出。     

电源及其系统

0611439 电压调节模块转换控制技术[刊,中]／何亮／／现代雷达．-2006,28(1)．-79-82(G) 微处理技术的不断发展,要求供电电源输出电压降低、输出电流增大、动态响应速度加快,由于多采用分布式电源系统,经过二次DC/DC变换实现对微处理     

新一代微处理器的电子电源——稳压电源模块(VRM)

新一代微处理器要求供电电源的输出电压低至1-2V,输出电流达50-100A,并且电流转换速率高。需要高效率、快速响应、高密度的低电压输出稳压电源模块(VRM)。为提高 VRM 的效率,输入电压为12V 的 VRM,广泛应用了同步整流 buck 变换器。多通道交错并联拓朴的电感小,可改进 VRM 的瞬态响应。输入电压为48V 的 VRM,应用有隔离变压器的电路拓朴,如有源钳位正激变换器、半桥变换器等。     

双电源管理系统的设计与实现

本文提出一个具有隔离功能的双电源管理系统,系统由控制器电路、隔离电路、切换电路和充电电路五部分构成。控制器实时监测主电源、备用电源电压与输出电流状态。主电源供电时,控制器控制充电电路向备用电源充电,使备用电源始终处于饱和状态;主电源发生故障时,控制器通过切换电路自动切换到备用电源向后续电路供电。隔离电路通过使用推挽式电源拓扑结构完成输入与输出的隔离,同时保证输出电压的稳定。系统提供RS485通信接口,运行Modbus标准协议,从而可以在远程实现对系统的控制。经实际测试,本系统具有切换时间短、供电电压稳定、隔离效果好、效率高等优点。     

两级式高效率数字电源的雷达系统应用

阐述高效率数字电源的设计,采用两级式架构,实现AC/DC电压变换功能,电源应用于地面雷达系统,可以适应大功率脉冲输出场景,并且具备输出电压在线快速切换功能。第一级电路采用交错并联BOOST拓扑实现功率因数校正;第二级电路采用半桥LLC拓扑实现隔离输出。在仿真平台经验参数验证并完成产品样机,在AC220V输入电压、输出满载2.5kW条件下功率因数0.998,THD小于3%,整机效率高达95.5%。     

隔离型DC/DC在高压电压电流源设计中的应用

由于隔离型DC/DC的安全性、隔离性等特征,该类器件广泛应用于多个电子、工业领域,本文主要介绍了隔离型DC/DC在高压电压电流源中的应用。本文将隔离型双输出DC/DC引入设计,利用DC/DC的隔离特性,将电压电流源的次级输出作为DC/DC器件参考地,将DC/DC器件的两路输出电压作为相关运算放大器的电源电压。常规高压电压电流源设计中需要大量采用高压运算放大器,采用此方案可使用较少的高压运算放大器及更低的成本实现相同功能,同时降低高压电源对PCB电路板上信号的影响。通过实际测量,文中方案输出稳定、精度高,满足设计与使用要求。文中用功能图纸对此类应用进行了详细说明。     

虚拟远端采样控制器

LT4180是虚拟远端采样DC／DC控制器,能连续查询线路阻抗,并校正稳压器的输出电压。该器件在负载端保持校正后的稳定电压,而不管电流或线路阻抗是多少。在采用隔离式或非隔离式电源的情况下,LT4180可与采用任何拓扑的稳压器一起工作。     

锂电池供电的高效、低纹波、低高频噪声电源设计

设计了一种锂电池供电的非隔离多路直流电源,嵌入到便携式移动设备中,电源有两路功率较大,效率、纹波、高频噪声的要求高。存在锂电池输出电压低时与电源输出电压较接近,普通的降压DC/DC难以实现的问题,设计采用了超低压差、占空比可达100%、高效率的BUCK变换器,解决了该问题。其中一路要求输出电压大范围可调、纹波小于1m V;设计采用了BUCK加LDO电路进行稳压,又明显减小了电源纹波;还用减法放大器控制BUCK电路,保持LDO的工作压差是较小的固定值,保证了电源的高效率。电源又增加了LC滤波和磁珠滤波,对进一步减小纹波和高频噪声的效果较好。     

基于DC/DC变换的逆变技术的研究

传统逆变器结构简单、技术成熟,但由于自身拓扑结构的不足使其存在开关损耗大、输出滤波要求高、输出交流幅值受电源电压限制、开关状态转换时可能出现直通短路等缺点。基于Buck的DC/DC变换器由于本身拓扑结构的优势,有效避免了传统逆变器的这些问题,进一步提高了效率。简要介绍了现有基于DC/DC变换器的逆变电路拓扑,并分析了各自拓扑结构的优缺点及相应的控制方式。     

一种四相交错并联BoostDC／DC变换器的设计

通信电源及分布式电源主要由前级高频整流器、中间级电池组和后级DC／DC变换器组成。DC／DC变换器的输入部分通常采用大功率Boost变换器,以将前级与中间级的直流电压提升至一定的幅度,从而更方便地形成所需提供给负载的各种电压。IntelCPU广泛用于IT工业,其对电源的要求越来越严格,需要提供更低的电压、更大的电流及更快的动态响应。为了改进Buck类型电压调整模块（Voltage Regulator Module,简称VRM）的动态响应要求,广泛使用多相交错并联技术,以实现快速的动态响应且极大地降低输出电流纹波。文章以一个大功率的四相交错并联Boost变换器作为设计实例,详细说明了其工作原理及主要器件的设计与选用;论证了该项技术用于BoostDC／DC变换器的多种优点,从而证明了多相交错并联技术的先进性和实用性。     

一种应用于直流电源的热替换与冗余新技术

文中以一个DC/DC 电源子系统的设计为例,说明了应用在DC/DC变换器模块上的热替换与冗余技术的工作原理.特别提出一种称为互补隔离的新冗余技术,以此来解决传统输出冗余二极管的隔离功率损耗大的缺陷问题.互补隔离技术法为在输出二极管两个端子上并联功率电磁继电器的一对常开触点,并用冗余控制信号对触点的闭合或释放状态进行控制.     

A novel current-sharing control technique for low-voltagehigh-current voltage regulator module applications

Future generations of microprocessors are expected to exhibit much heavier loads and much faster transient slew rates. Today's voltage regulator module (VRM) will need a large amount of extra decoupling and output filter capacitors to meet future requirements, which will basically make the existing VRM topologies impractical. As a candidate topology, the interleaved quasisquare-wave (QSW) VRM exhibits very good performance, such as a fast transient response and a very high power density. The difficulty with the application of the interleaved parallel technology is the current-sharing control. In this paper, a novel current-sensing and current-sharing technique is proposed. With this technique, current sharing can be controlled simply in parallel converters without a current transformer and current-sensing resistors. In addition, this technique can be easily integrated with an IC chip. The four-module paralleled QSW VRM is used to evaluate this technique. Experimental results verify that with this technique, the VRM has a high power density, high efficiency and a fast transient response. The concept of the current sharing technique is also generalized and extended     

A hybrid 4-in-1 DC?DC controller chip for a PC mainboard

The DC–DC converter is a fundamental component of the personal computer (PC) mainboard and occupies a large part of its area. To increase the integration and reduce the cost of PC mainboards, a new hybrid 4-in-1 DC–DC power controller integrated circuit is designed, which integrates a programmable synchronous buck switching controller, a standard buck switching controller, a linear controller and a linear regulator with an on-chip MOS switch into one chip. It provides the complete solution of control, output adjustment, output monitoring and overcurrent/over-voltage protections for the four power supplies on a PC mainboard. The chip is designed and fabricated in the 1.7µm BiCMOS process. Test results of the established hybrid power system for PC mainboards show that the programmable synchronous switching regulator has fast transient response, small startup overshoot, high conversion efficiency and high precision of 0.8% under full load range. It meets the specifications of Intel's VRM8.4 design guidelines for the power supply of high-performance Pentium III central processing units. The standard switching regulator and the other two linear regulators also have high precision and small startup overshoots, they are suitable for providing voltages for the I/O, GTL bus and clock generator respectively on the PC mainboard.     

Investigation of candidate VRM topologies for futuremicroprocessors

By reducing the power supply voltage, faster, lower power consumption, and high integration density data processing systems can be achieved. The current generation high-speed complementary metal-oxide-semiconductor (CMOS) processors (e.g., Alpha, Pentium, Power PC) are operating at above 300 MHz with 2.5 to 3.3 V output range. Future processors will be designed in the 1.1-1.8 V range, to further enhance their speed-power performance. These new generation microprocessors will present very dynamic loads with high current slew rates during transient. As a result, they will require a special power supply, voltage regulator module (VRM), to provide well-regulated voltage. The VRMs should have high power densities, high efficiencies, and good transient performance. In this paper, the critical technical issues to achieve this target for future generation microprocessors are addressed. A VRM candidate topology, interleaved quasisquare-wave (QSW), is proposed. The design, simulation and experimental results are presented     

Improved light-load efficiency for synchronous rectifier voltageregulator module

DC/DC converter with high efficiency over a wide load range is necessary for many low voltage applications, such as battery supplied systems and micro-processor power supplies-voltage regulator module (VRM). In order to improve the efficiency of low voltage converters, synchronous rectifier technology is widely used. The disadvantage of this technology is low efficiency at light load. This paper proposes a new technology, which utilizes the duty cycle signal, to improve light load efficiency with simple implementation. Since current sensors are not required, high density and high efficiency can be achieved that makes the whole circuit suitable for integration. In the paper, two application examples are given. Experimental results verified that the proposed control schemes significantly improve the efficiency of synchronous rectifier buck converters at light load     

降压型DC/DC开关电源中的电压前馈技术

介绍了一种应用于降压型DC/DC开关电源的电压前馈技术,通过调整内部三角波的中心电压,使PWM信号占空比跟随输入电源电压快速改变。该技术能有效抑制输入电源电压变化对输出电压的影响,增强输出电压的稳定性。     

带变反射率耦合输出镜的连续高功率Nd：YAG激光器的研究

分析了具有变反射率耦合输出镜（ＶＲＭ）的热透镜谐振腔的光束传输特征，研究了ＶＲＭ的耦合输出及对高功率固体激光光束的选模作用，实验结果验证了理论分析并得到连续波１８０Ｗ，光束参数乘积（远场发散角半角×近场光束半径）为６．２５ｍｍ·ｍｒａｄ的高亮度激光输出。     

多单片机直流电源控制板设计

介绍了一种以单片机控制晶闸管触发脉冲为核心的直流电源控制板系统,该系统实现了晶闸管触发脉冲信号的同步产生、移相、驱动以及系统过压／过流保护等功能。用户可通过键盘来设置直流电源的输出,八段数码管显示实际输出电压／电流值;在硬件与软件的配合设计下,该系统实现了智能化三相交流电的相序判断、同步脉冲形成、断线检测、脉冲编码计算、输出数据采样、软启动控制及比例控制等功能。     

数控直流稳压电源设计

常规线性稳压电源中,调整元件串联在负载回路,其作用就像一只可变电阻,输入电压或负载变化时,串联调整元件的压降改变,从而使输出电压稳定不变。当输入电压过高时,串联调整管的功耗很大,因此效率很低。为了解决常规线性电源采用滑动电阻调节方式所带来的低效率问题,通过采用数字控制的方法,使线性电源的效率最大化。该设计利用STC12C5410AD单片机输出PWM控制三端稳压器,实际带载测试在输入电压波动范围为±20%的情况下,效率达到了50%的结果,证明数控型电源具有工作稳定,电压调节精度高,纹波系数小,效率高于常规线性电源的特点。