三端集成稳压器扩流方法分析

以LM317K进行电流扩展为例介绍了三端集成稳压器的3种扩流方法,即晶体管扩流、电阻扩流和并联扩流。通过扩流解决了三端集成稳压器输出电流由于受限而不能满足设计要求的问题。给出了3种扩流方法的具体电路连接及原理分析。对LM317K设计的不同方案的扩流电路均使用Multisim V10软件进行了仿真,从仿真结果可以看出3种扩流方法的可行性和正确性。通过对3种扩流方法的分析和比较,给出了各自适用的场合和使用的注意事项。在实际应用中,可根据扩流的大小和使用的三端集成稳压器的型号来选择合适的扩流方法。     

集约型51系统板输出通道的改进设计

针对目前51系统板输出通道的设计问题,该设计以硬件集约、性价比高、操作容易为原则,创新设计了ISP下载、集约型显示输出、开关信号输出、模拟信号输出等电路。并对LCD电路、LED电路、D/A电路做了元器件比较选择和较大改进,使设计的系统板具有成本低、简单易用的优点。整个输出通道包含LCD显示、LED数码管显示、LED点阵显示3种显示输出、开关量输出、模拟量输出等模块,非常适合在基于单片机的嵌入式系统中应用。     

TM310高次模圆柱形谐振腔耦合矩形波导输出回路研究

设计了适用于多注速调管,工作在TM310高次模圆柱形谐振腔耦合矩形波导输出回路,其工作中心频率为7 585.3 MHz,计算了腔体内各漂移管间隙阻抗的频率特性,并分析了输出回路的输出带宽.研究结果表明: 在相同频率条件下,采用圆柱形TM310工作模式的谐振腔体积将是采用圆柱形TM010工作模式谐振腔体积的7倍;TM310高次模圆柱形谐振腔耦合矩形波导后,各漂移管特性阻抗与耦合前相比有稍微变化,但耦合后各间隙特性阻抗非常接近;反射系数相位法及等效电路法计算输出腔外观品质因数分别为为154和160,输出中心频率7 585.263 MHz,比耦合前腔体谐振频率降低26.525 MHz,输出带宽约为3%,因此,该类型输出回路比较适合用作高射频段的窄带多注速调管.     

输出整流器占空比与反激式开关电源损耗关系的分析

该文通过分析输出整流器的导通占空比和变压器二次侧损耗、输出整流器导通损耗、输出滤波电容器损耗的关系,来调整输出整流器的导通占空比,优化输出端参数,降低反激式开关电源损耗.其有效性通过saber仿真实验得以验证.     

高功率微波源功率输出自动控制系统

高功率微波源功率输出控制技术在微波化学领域相当重要。但是，由于产生大功率微波的技术和工艺相当复杂，特别是使用中微波磁控管工作条件的改变会导致输出功率的涨落．若没有完善的控制电路和控制方法要获得比较稳定的功率输出是难以达到的．而在实际应用中我们希望获得稳定的功率输出来使化学反应稳定进行。介绍一种单片机控制系统电路，该电路通过对输出功率进行采样、处理并运用增量式PID技术计算出控制参数，根据控制参数调节磁控管的磁场电流大小，最终达到控制大功率微波源输出功率的目的。该控制电路使功率源的输出功率得到自动控制，并获得了比较稳定的功率输出．     

大模面积双包层光纤激光器性能的实验研究

基于大模面积双包层Er3+/Yb3+共掺光纤,采用P-F腔结构,详细研究了工作温度、光纤弯曲对泵浦吸收和激光输出性能的影响。结果表明:随着泵浦功率的增大,输出光谱的模式逐渐增多;泵浦源的工作温度决定其输出光谱特性,进而影响光纤激光器的输出效果;光纤不同激光模式对应不同光纤弯曲损耗,当弯曲半径减小到一定程度时,多模输出变成单模输出,由此提高输出光束质量。     

一种恒压输出的DC-DC升压电路设计

针对DC-DC升压器存在效率低,纹波电压较大,输出电压不稳定等问题,文中开发和设计了一种具有恒定输出电压的DC-DC升压转换器的方法。通过升压电路和电压反馈技术,将波动的输入电压变成恒定的直流电压输出。该设计通过将转换器的输出电压与参考电压相比较,两者的差值会产生一个PWM信号控制升压器的通断时间,从而达到恒定电压输出。仿真结果显示,该实验电路能在频率为20 kHz的连续导通模式中工作,产生24 V的恒定输出电压,输出功率为100 W。     

Output Impedance Design of Parallel-Connected UPS Inverters With Wireless Load-Sharing Control

This paper deals with the design of the output impedance of uninterruptible power system (UPS) inverters with parallel-connection capability. In order to avoid the need for any communication among modules, the power-sharing control loops are based on the$P/Q$droop method. Since in these systems the power-sharing accuracy is highly sensitive to the inverters output impedance, novel control loops to achieve both stable output impedance and proper power balance are proposed. In this sense, a novel wireless controller is designed by using three nested loops: 1) the inner loop is performed by using feedback linearization control techniques, providing a good quality output voltage waveform; 2) the intermediate loop enforces the output impedance of the inverter, achieving good harmonic power sharing while maintaining low output voltage total harmonic distortion; and 3) the outer loop calculates the output active and reactive powers and adjusts the output impedance value and the output voltage frequency during the load transients, obtaining excellent power sharing without deviations in either the frequency or the amplitude of the output voltage. Simulation and experimental results are reported from a parallel-connected UPS system sharing linear and nonlinear loads.     

单圈T函数生成序列的自相关性(英文)

Cryptographic properties of the single cycle T-function's output sequences are investigated.Bounds of autocorrelation functions of the kth coordinate sequence and bounds of state output sequence are calculated respectively.The Maximum Sidelobe Ratio(MSR) of the kth coordinate sequence and the MSR of state output sequence are given respectively.The bounds of autocorrelation functions show that the values of autocorrelation functions are large when shifts are small.Comparisons of the autocorrelations between ...     

高速D/A转换器输出跨导模型及对无杂波动态范围的影响

基于无缓冲差分输出电流舵D/A转换器,建立电流源及输出电路的s域线性模型,分析输入码变化所引起的输出跨导的变化,以及对输出电流的影响。采用直流和交流量分离的方法,利用傅里叶级数,获得输出跨导对无杂波动态范围(SFDR)的影响的近似公式。采用Matlab建立高层次模型进行仿真验证。结果表明,输出跨导较大时,输出跨导与SFDR呈近似线性关系。     

基于推挽拓扑的输入并联输出串联直流变换器及其输出均压控制策略分析

在输出高电压场合,将较低的输入直流电压变换为较高的直流电压输出。输出端由于存在高压使得输出端器件承受较大的电压应力,存在变换器次级电压偏高、整流二极管电压应力大以及反向恢复时间长等问题。 基于此问题,提出以推挽变换器为基本单元,采用多个基本单元推挽变换器构成的输入串联输出并联变换器。为了确保该变换器系统的稳定可靠,从能量守恒的角度出发,分析了该变换器中各模块的输出均压之间的关系,给出了输出均压的实现条件。通过建立系统小信号模型,推导出系统的稳定条件,最后经试验验证了理论分析的正确性。     

Slew-Rate-Controlled Output Driver Having Constant Transition Time Over Process, Voltage, Temperature, and Output Load Variations

A slew-rate-controlled output driver having a constant transition time irrespective of environmental variations is described in this brief. The proposed output driver employs a capacitive feedback between the output and input of the driver to allow its transition time independent of process, voltage, temperature and output load variations. The proposed output driver was designed and fabricated using a 0.13-mum CMOS process. According to our experimental results, the normalized variation on transition time of the proposed output driver due to PVT variations was improved by 74%-80% as compared to the conventional output driver. The comparison result also indicates that the normalized variation on transition time due to output load change from 10 to 100 pF (10 times variation) in typical process, voltage and temperature corners was improved by up to 66%.     

High-speed, low-switching noise CMOS memory data output buffer

This paper describes a data output buffer for highspeed CMOS integrated memories with a high data output pin count. The buffer minimizes the switching noise induced on supply lines while achieving very fast output transitions by combining output presetting techniques together with adequate driving of the output pull-up and pull-down transistors. Tristate operation and zero static power consumption are also provided. The buffer was integrated in a 16-Mb EPROM device. It occupies 0.06 mm² and ensures a better than 15 ns output transition time with a load capacitor of 100 pF     

Hard-limiting of two signals in random noise

Two sinusoidal signals and Gaussian noise lying in a narrow band are passed through an ideal band-pass limiter that confines the output spectrum to the vicinity of the input frequencies. The output spectrum, consisting of both discrete and continuous components, is studied in terms of its corresponding autocorrelation function. The discrete output components are identified with the output signals and intermodulation products due to interference between the two input signals. The continuous part of the spectrum is associated with the output noise. The effects of limiting are expressed by ratios among the average powers of the output spectral components. Performance curves are given that show signal suppression, the ratio of output to input SNR's, and the relative strength of the intermodulation terms.     

采用二相功率时钟的无悬空输出绝热CMOS电路

分析了PAL及PAL-1电路中输出悬空对电路性能的影响,强调在绝热电路设计中消除悬空输出的重要性．提出了两种新的结构互补且无悬空输出的绝热电路．PSPICE模拟证明它们能有效实现能量恢复,并使输出信号在整个有效输出期始终处于箝位状态．     

采用二相功率时钟的无悬空输出绝热CMOS电路

分析了 PAL 及 PAL- 1电路中输出悬空对电路性能的影响 ,强调在绝热电路设计中消除悬空输出的重要性 .提出了两种新的结构互补且无悬空输出的绝热电路 .PSPICE模拟证明它们能有效实现能量恢复 ,并使输出信号在整个有效输出期始终处于箝位状态     

High-speed rail-to-rail output buffer amplifier with dynamic-bias circuit

The design of a high-speed output buffer amplifier for driving the large column line loads of large-size TFT-LCDs is presented. The major circuit of the output buffer is a rail-to-rail current mirror amplifier which can control the class-AB output stage and auxiliary output stage at the same time. The proposed dynamic bias method not only increases the driving capability of the class-AB output stage but also maintains a small quiescent current path.     

基于自动识别主辅路同步控制的正激变换器

为了改善多路输出正激变换器交叉调整率,提出了一种基于ARM自动识别主辅路同步控制的控制策略。利用ARM实时采样各路输出端的实时输出电压和负载电流,计算每一路的输出功率,根据设定的判断规则,设别出主路和辅路。主路采用PID电压环控制方法,ARM输出相应的PWM波驱动主开关和同步整流开关。对辅路采取了副边电压环控制,产生相应的使能信号控制辅路同步整流开关是否接受驱动信号,以提高辅路输出的电压精度,以及减小相应的交叉调整率。实验结果表明,利用该控制策略所设计的双路输出正激变换器获得了小于5.5%的交叉调整率。     

大功率CO2激光器输出窗口热性能分析

为了研究大功率CO2激光发射过程中输出窗口吸收激光能量产生热性能变化的问题,建立了输出窗口传热学和结构力学耦合非稳态模型,通过对模型进行有限元分析得到表征输出窗口变化的温度、热变形和热应力等参数分布。首先,针对大功率CO2激光特点,讨论了输出窗口材料GaAs和ZnSe的物理特性。然后,基于10 kW级大功率CO2激光器光学谐振腔结构和输出窗口材料物理特性,建立了输出窗口传热学和结构力学的有限元模型。最后,利用COMSOL软件对该模型进行求解,得到以GaAs和ZnSe为材料的输出窗口的温度、热变形和热应力等参数分布,并对比分析不同窗口材料对参数的影响。研究表明:在10 kW级激光作用下,ZnSe窗口温升小于GaAs窗口;两种输出窗口产生m量级热变形;由于GaAs材料的热导率高,GaAs窗口的热变形和热应力分布更为均匀。     

The overall small-signal model of the synchronous switchpostregulator

The overall small-signal models of the synchronous switch postregulators (SSPRs) with leading-edge or trailing-edge modulation are developed. From the models, the effect of the main output to the auxiliary output when the SSPR is operated in the continuous conduction mode or in the discontinuous conduction mode can be predicted. Once the main output enters into the discontinuous mode, the performances of the auxiliary output will degrade very much, even with the help of the postregulation, but if only the auxiliary output enters into the discontinuous mode, the performance degradation of the auxiliary output can be less severe