凌力尔特推出采用单电感器的高效率同步降压-升压型DC/DC控制器

凌力尔特公司（Linear Technology）推出效率非常高（可达98%）的同步降压-升压型DC/DC控制器LTC3789,该器件以高于、低于或等于稳定输出电压的输入电压工作。大功率升压和降压电路一般依靠变压器或两个DC/DC转换器工作,一个用于升压转换,另一个用于降压转换。     

通用控制器简化高压DC/DC转换器设计

引言LT3724是单开关DC/DC控制器,可用于实现中等功率的降压、升压、负输出和SEPIC转换器拓扑。它可组成简单的解决方案,可在宽输入电压范围(4V-60V)和宽负载范围内以高效率调节系统电压。     

基于8位微控制器的参数自调整模糊控制DC/DC变换器

提出了一种基于8位微控制器实现的用于控制DC／DC变换器输出电压的参数自调整模糊控制方法。用参数自调整的策略来优化常规模糊控制器，提高了DC／DC变换器的控制性能。实验结果表明，所提出的新控制方法不仅具有良好的控制性能，而且容易用成本较低的8位微处理器来实现。     

固定频率PWM微功率DC／DC变换器设计

在电池供电的计算机、消费类产品和工业设备中,DC／DC变换器是重要的部件。变换器有两种类型：线性变换器和开关变换器。开关变换器主要有三种拓扑结构：降压变换器（开关稳压器将一输入电压变换成一较低的稳定输出电压）;升压变换器（开关稳压器将一输入电压变换成一较高的稳定输出电压）;逆向变换器（开关稳压器将一输入电压变换成一较低的稳定反相输出电压）。在此用Motorola的MC33466微功率开关稳压器来设计降压变换器、升压变换器和逆向变换器。MC33466器件具有非常低的静态偏置电流（典型值15pA）,含有高精度电压基准、振荡器…     

绛压式DC／DC转换器的MOSFET选择

同步整流降压式DC／DC转换器部采用控制器和外接功率MOSFET的结构。控制器生产商会在数据资料中给出参数齐全的应用电路，但用户的使用条件经常与典型应用电路不同，要根据实际情况改变功率MOSFET的参数。     

微型降压式DC/DC模块LTM46OO

一般的DC/DC变换器集成电路由控制器、MOSFET开关管及一些功能电路组成.近年来,DC/DC变换器采用了同步整流技术,又集成了同步整流的MOSFET.凌特公司最近开发出一种微型降压式DC/DC模块,它不仅集成了控制器、开关及同步整流MOSFET及各种功能电路,并且还把可输出10A电流的电感器、软启动电容器做在一个贴片式IC中,外部只要接上输入、输出电容器及一个设定输出电压的电阻就成为完整的DC/DC模块电源.本文介绍这种微型DC/DC模块LTM4600及其应用电路.     

多媒体时代便携设备用DC／DC变换器

为了把电池电压高效地变换为所需的电压,便携式设备采用了能够进行升压、降压和升降压的DC/DC变换器。近年来,使用2节甚至1节碱性电池的便携式设备日渐增多,从而对其电源电路的效率提出了更高的要求。 对于使用1节电池的便携式设备而言,它们采用的是可利用0.9V进行升压的控制IC。作为控制方式寻呼机、立体声耳机、MD机分别适用PFM(脉冲频率调制)控制、PWM(脉宽调制)控制和PWM/     

NJM2360贴片式DC/DC变换器IC

<正> NJM2360是日本JRC公司的新产品,是一种既能升压、降压又能作电压反转的通用DC/DC变换器LC。它的特点是:内部有一个1.5A大电流的开关管;可用以组成各种功能变换器,而且外围元件很少;输出电流可通过外设一电阻来限制;贴片式SO—8封装,尺寸小。     

一种新型交错并联单输入高升压DC/DC变换器设计

针对传统的交错并联升压直流变换器输出电压低,开关器件电压应力高等不足之处,提出一种新型交错并联单输入高升压直流变换器.通过开关电感单元替代传统电感、变换器后级增加电容和二极管构成升压单元,提高变换器输出电压.所提DC/DC变换器中开关器件电压应力和二极管电压应力有效降低,升压增益有效提高.同时,该变换器具有元器件简单对...     

采用单电感器同步降压－升压型DC／DC控制器

LTC3789以高于、低于或等于稳定输出电压的输入电压工作。大功率升压和降压电路一般依靠变压器或两个DC／DC转换器工作,一个用于升压转换,另一个用于降压转换。     

Adaptive output voltage tracking controller for uncertain DC/DC boost converter

This paper presents a cascade output voltage control strategy for an uncertain DC/DC boost converter adopting an adaptive current controller in its inner loop. Considering the non-linearity, load uncertainties and parameter uncertainties of the converter, the proposed controller is designed following the conventional cascade voltage controller design method. The proposed method makes the following three contributions. First, a coordinate transformation is introduced for the inner loop, enabling avoidance of the singularity problem caused by the estimates of uncertain parameters. Second, a slight modification to the adaptation law is performed to guarantee closed-loop stability in the presence of the time-varying component of the load current. Third, the outer-loop controller is devised such that its performance can be adjusted without any parameter information. The closed-loop performance is demonstrated through simulations and experiments using the DSP28335 with a 3 kW DC/DC boost converter.     

用开关电容网络改善DC-DC变换器性能的研究

将串并电容组合结构,极性反转开关电容网络和推挽开关电容网络和ｂｕｃｋ,ｂｏｏｓｔ,Ｃｕｋ及ｂｕｃｋ－ｂｏｏｓｔ等传统ＤＣ－ＤＣ变换器相结合,构成一系列新的变换器拓扑结构。理论分析和实验结果秀助于提高具有悬殊电压变化比的ＤＣ－ＤＣ变换器的工作频率和动态响应,还能拓宽变换器的电压变换范围。     

开关电容DC—DC变换器的效率

将开关电容网络应用到ＤＣ－ＤＣ变换器，并从能量的角度研究了其效率，得出一个对所有类型的开关电容变换器的适用的公式，提出了改善效率的新的拓扑结构，使升压与降压开关电容变换器有较高的效率，实验结果与计算机模拟均取得了与分析相同的结果。     

Modeling PWM DC/DC converters out of basic converter units

An alternative approach to modeling pulsewidth-modulated (PWM) DC/DC converters out of basic converter units (BCUs) is presented in this paper. Typical PWM DC/DC converters include the well-known buck, boost, buck-boost, Cuk, Zeta, and Sepic. With proper reconfiguration, these converters can be represented in terms of either buck or boost converter and linear devices, thus, the buck and boost converters are named BCUs. The PWM converters are, consequently, categorized into buck and boost families. With this categorization, the small-signal models of these converters are readily derived in terms of h parameter (for buck family) and g parameter (for boost family). Using the proposed approach, not only can one find a general configuration for converters in a family, but one can yield the same small-signal models as those derived from the direct state-space averaging method. Additionally, modeling of quasi-resonant converters and multiresonant converters can be simplified when adopting the proposed approach     

一种新型交错并联同相降压升压DC/DC转换器

为了有效降低电流纹波和提高转换器效率,提出一种新型交错并联同相降压升压DC/DC转换器。提出的结构通过采用输入/输出（I/O）磁耦合交错并联和阻尼网络技术,降低了开关的电压应力、内部电压振荡和I/O电流纹波,并提升了转换器的效率。采用状态空间平均法,在连续导通模式下分析了提出转换器的稳态运行,从理论上证明了其优势。样机的功率设置为360W,输出电压为36 V,模拟结果以及实验结果显示,当输出电流为6A时,转换效率最高达到96%,最大输入电流纹波百分比仅为9.4%,相较于其他类似转换器,提出的转换器具有效率较高和I/O电流纹波较低的优势。     

基于DSP直流电机速度的模糊控制系统研究

介绍一种基于模糊控制的直流电机速度控制系统。该模糊控制器设计为二维模糊控制器,以速度反馈和给定转速的误差及误差的变化率作为模糊控制器的输入变量,采用带调整因子的模糊控制器不需要建立模糊查询表。运用DSP强大的计算能力直接按实时计算输出控制量,实现编码器的解码、速度的测量。试验表明系统具有较强的鲁棒性和抗干扰能力,适应于各种不同的场合。     

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。     

Optimal feed-forward compensation for PWM DC/DC converters with`linear' and `quadratic' conversion ratio

An analytical procedure to optimize the feedforward compensation for any PWM DC/DC power converters is described. Achieving zero DC audiosusceptibility was found to be possible for the buck, buck-boost, Cuk, and SEPIC cells; for the boost converter, however, only nonoptimal compensation is feasible. Rules for the design of PWM controllers and procedures for the evaluation of the hardware-introduced errors are discussed. A PWM controller implementing the optimal feedforward compensation for buck-boost, Cuk, and SEPIC cells is described and fully experimentally characterized     

Design and Realization of Stand-Alone Digital Fractional Order PID Controller for Buck Converter Fed DC Motor

The aim of paper is to employ digital fractional order proportional integral derivative (FO-PID) controller for speed control of buck converter fed DC motor. Optimal pole-zero approximation method in discrete form is proposed for realization of digital fractional order controller. The stand-alone controller is implemented on embedded platform using digital signal processor TMS320F28027. The five tuning parameters of controller enhance the performance of control scheme. For tuning of the controller parameters, dynamic particle swarm optimization technique is employed. The proposed control scheme is simulated on MATLAB and verified by experimental results. Performance comparison shows better speed control of separately excited DC motor with the realized digital FO-PID controller than that of the integer order PID controller.