PDP子场数据自适应优化低功耗寻址方法

为降低等离子体显示器(PDP)的寻址功耗,在分析PDP寻址功耗和图像信息在各子场分布特征的基础上,根据人眼视觉在不同背景亮度下对图像信息感知能力不同的特点,提出了子场数据自适应优化低功耗寻址方法.该方法在图像质量变化不影响视觉感知的情况下,根据图像寻址功耗的预设目标和实际值,自适应选择寻址功耗的优化级别,通过减少低权重子场数据变化率来降低PDP寻址功耗.该方法仅需对寻址数据的算法进行优化,无需改动硬件和驱动波形,在50英寸WXGA单扫PDP模组上对IEC标准动态视频的寻址功耗进行测试,结果表明,该方法可使IEC标准动态视频的寻址功耗平均降低8.17％,最大降低25.8W.     

彩色等离子体显示器寻址功耗等效电路模型

彩色等离子体显示器中引起的容性电流构成了寻址IC中MOS管开关电流的主体,以此为基础建立了寻址功耗等效电路模型,得到寻址功耗计算公式。典型图案寻址功耗的实验结果表明,寻址功耗和各子场图像数据在列方向上的变化率,以及相邻列之间寻址数据差在列方向上的变化率成正比,和图像信号的平均强度没有关系。寻址功耗的理论计算值和实验结果一致,寻址等效电路模型能够对不同图案的寻址功耗进行合理的解释,解决了寻址功耗检测对象不确定和检测的准确性问题。     

彩色PDP中的重复行技术及其实现

对于采用ADS技术的彩色PDP ,增加子场数目能够有效地消除动态假轮廓的影响 ,但增加子场数目将使寻址时间增大、维持发光时间减少 ,从而使彩色PDP的亮度降低。采用重复行技术能够有效缓解寻址时间与维持时间之间的矛盾 ,在寻址时间不变的情况下增加子场数目 ,本文详细分析了一种实用的重复行技术及其最小误差算法     

彩色PDP中的重复行技术及其实现

对于采用ADS技术的彩色PDP，增加子场数目能够有效地消除动态假轮廓的影响，但增加子场数目将使寻址时间增大、维持发光时间减少，从而使彩色PDP的亮度降低。采用重复行技术能够有效缓解寻址时间与维持时间之间的矛盾，在寻址时间不变的情况下增加子场数目，本文详细分析了一种实用的重复行技术及其最小误差算法。     

荫罩式PDP单元放电过程中电极电流的模拟

本文采用二维流体模型研究荫罩式PDP(SMPDP)结构放电单元内的放电过程,并在此基础上与表面电荷法结合模拟各电极上的电流.给出了寻址周期和维持周期各电极上的电流变化过程.研究了在不同寻址电压下各电极电流变化情况,分析了电流峰值的大小和电压的关系及到达电流峰值的时间和电压的关系.得到的SMPDP放电单元各电极上电流变化的规律,可用于优化驱动电压波形和改进单元结构.     

应用于等离子体显示器的铝电极及其介质层制备研究

提出用铝取代银作为寻址电极,氧化铝取代玻璃粉作为其上介质层的新型等离子体显示器(PDP)电极单元,对单项工艺进行了优化,并形成了完整可行的整体工艺路线,有望为PDP生产成本的降低提供一条新的技术途径.选用非连续磁控溅射和光刻-刻蚀工艺制备铝电极,阳极氧化工艺制备氧化铝介质层.用扫描电子显微镜对铝膜、氧化铝介质层及电极单...     

51单片机寻址方式

我们已经知道,单片机的工作过程就是一条一条地从ROM存储器中取出指令然后执行相关的操作。一般来说,一条指令总是有操作码字段和操作数字段两部分组成,单片机执行指令时就根据指令中给出的地址寻找实际的操作数,寻址方式就是根据指令中给出地址寻找操作数地址的方式。根据指令操作的需要,计算机有多种寻址方式。总的来说,寻址方式越多,计算机的功能就越强,灵活性越大,指令系统也越复杂,而本文主要介绍的是51单片机指令系统中的7种寻址方式。     

PDP单元寻址期放电特性的研究

本文基于帕邢定律,采用数值模拟的方法,计算了放电单元内,沿不同放电路径着火电压的分布情况.结合流体模型,研究了寻址期ACCPDP中X电极偏压,对寻址放电以及壁电荷积累的影响.模拟结果表明,寻址期间,在ACCPDP的X电极加一定的正偏压(VX),能达到较好的壁电荷积累,从而降低维持期工作电压.在理论计算的基础上,本文基于气体放电相似性定律,设计和制作了ACCPDP放大单元.拍摄了ACCPDP寻址放电过程,并研究了不同VX偏压对于寻址放电影响.实验得到的放电过程中光发射分布,也间接证明了模拟结果的正确性.     

荫罩式等离子体显示板寻址放电延迟时间的研究

高氙浓度是提高等离体显示器亮度和发光效率的有效手段,但必须关注高氙比例对寻址放电延迟的影响。本文采用7英寸小屏实验平台研究氙比例增加对寻址放电延迟的影响,分析了氙比例增加,寻址电压和维持电压变化条件下,寻址放电的形成性延迟和统计性延迟的变化规律。研究结果表明寻址形成性延迟随寻址电压和维持电压的增加而减小,随氙比例的增加而增加,寻址形成性延迟时间与电子在一个平均自由程内获得的电场能量成反比。而寻址统计性延迟随寻址电压、维持电压的变化基本保持不变,随氙比例的变化规律性不明显,说明氙比例不是寻址统计性延迟的主要影响因素。研究表明荫罩式等离子体显示屏即使在50%氙比例时,仍可实现1.6μs的寻址。     

新型PDP放电单元着火特性的研究

采用数值方法 ,研究了新型荫罩式PDP(SM PDP)放电单元的着火特性 ,并与传统表面放电式PDP(ACC PDP)作了比较。计算了沿不同放电路径下的气体着火电压 ,讨论并分析了两种结构中 ,某些结构参数的变化对于着火特性的影响。模拟发现 ,SM PDP单元的着火电压要低于ACC PDP ,且在两种结构中 ,电极间距、放电空间大小、介质层对着火电压的影响程度也有一些不同。     

低功耗高速时钟数据恢复电路

为了降低高速串行接口的时钟数据恢复(CDR)电路的功耗,在研究、分析现有时钟数据恢复结构的基础上,提出了一种新的时钟数据鉴相算法及其电路实现方法。新的电路设计仅使用一个高速采样时钟,比传统的鉴相电路减少一半的采样率,从而减少了前端采样模块的功耗。该鉴相算法采用统计方法减小鉴相时钟的噪声,进而达到很低的误码率。该鉴相算法可使用数字综合的方法实现,工作在较低的频率下,这样便于迁移到不同的工艺中。整个电路使用40nm工艺实现,实际芯片测试数据表明,使用该电路的接收端可以稳定工作在13Gb/s的速率下,功耗达到0.83p J/bit,误码率低于10E-12。     

Energy dissipation and transport in nanoscale devices

Understanding energy dissipation and transport in nanoscale structures is of great importance for the design of energy-efficient circuits and energy-conversion systems. This is also a rich domain for fundamental discoveries at the intersection of electron, lattice (phonon), and optical (photon) interactions. This review presents recent progress in understanding and manipulation of energy dissipation and transport in nanoscale solid-state structures. First, the landscape of power usage from nanoscale transistors (∼10⁻⁸ W) to massive data centers (∼10⁹ W) is surveyed. Then, focus is given to energy dissipation in nanoscale circuits, silicon transistors, carbon nanostructures, and semiconductor nanowires. Concepts of steady-state and transient thermal transport are also reviewed in the context of nanoscale devices with sub-nanosecond switching times. Finally, recent directions regarding energy transport are reviewed, including electrical and thermal conductivity of nanostructures, thermal rectification, and the role of ubiquitous material interfaces.      

相变材料导热性能强化的研究进展

相变储能复合材料对于缓解能源紧张状况,保护环境和提供舒适健康的生活环境具有积极的意义,在太阳能热发电、工业热利用及余热回收方面有显著优势。但是相变材料本身存在导热性能不高,容易腐蚀容器等问题,所以本文主要综述了相变材料导热性能强化的研究进展。首先介绍相变储能材料的现状以及存在的问题,然后讨论了以金属、陶瓷和碳质纳米材料作为导热强化材料在相变储能复合材料中的研究现状和成果,最后展望了经导热强化后的相变储能复合材料的前景。     

石墨烯、超声波缓和木糖醇过冷性的研究

中高温相变储能技术对于能源的开发和合理利用具有重要的意义,在太阳能热发电、工业热利用及余热回收方面有着显著优点。作为相变储能材料的木糖醇在凝固放热过程中有强烈的过冷倾向,不产生任何结晶。本研究采用超声波照射和添加石墨烯的方法缓和过冷,并进行了试验研究。试验结果显示,超声波和石墨烯均能有效缓和木糖醇的强过冷倾向,激发木糖醇成核结晶,并且最初的成核结晶位置与超声波和石墨烯作用相关。     

Analog-digital and digital-analog converters using single-electron and MOS transistors

This paper proposes two kinds of novel single-electron analog-digital conversion (ADC) and digital-analog conversion (DAC) circuits that consist of single-electron transistors (SETs) and metal-oxide-semiconductor (MOS) transistors. The SET/MOS hybrid ADC and DAC circuits possess the merits of the SET circuit and the MOS circuit. We obtain the SPICE macro-modeling code of the SET transistor by studying and fitting the characteristics of the SET with SPICE simulation and Monte Carlo simulation methods. The SPICE macro-modeling code is used for the simulation of the SET/MOS hybrid ADC and DAC circuits. We simulate the performances of the SET/MOS hybrid 3-b ADC and 2-b DAC circuits by using the H-SPICE simulator. The simulation results demonstrate that the hybrid circuits can perform analog-digital and digital-analog data conversion well at room temperature. The hybrid ADC and DAC circuits have advantages as follows: 1) compared with conventional circuits, the architectures of the circuits are simpler; 2) compared with single electron transistor circuits, the circuits have much larger load capability; 3) the power dissipation of the circuits are lower than /spl omega/W; 4) the data conversion rate of the circuits can exceed 100 MHz; and 5) the resolution of the ADC and DAC circuits can be increased by the pipeline architectures.     

Simple circuits for generating high-voltage staircase waveforms

Two novel circuits are described which provide simple generation of high-voltage staircase waveforms for driving electro-optical (EO) loads. The circuits use power MOSFET's in what is essentially a switching mode. For applications which require high-voltage step-type waveforms, this technique offers substantial power savings and improved time-domain response over drive circuits that use a linear amplifier approach. Waveform characteristics can be controlled at a low voltage point, allowing flexible and accurate operation     

Power-efficient dual-rate optical transceiver

A dual-rate (2 Gbit/s and 100 Mbit/s) optical transceiver designed for power-efficient connections within and between modern high-speed digital systems is described. The transceiver can dynamically adjust its data rate according to performance requirements, allowing for power-on-demand operation. Dynamic power management permits energy saving and lowers device operating temperatures, improving the reliability and lifetime of optoelectronic-devices such as vertical-cavity surface-emitting lasers (VCSELs). To implement dual-rate functionality, we include in the transmitter and receiver circuits separate high-speed and low-power data path modules. The high-speed module is designed for gigabit operation to achieve high bandwidth. A simpler low-power module is designed for megabit data transmission with low power consumption. The transceiver is fabricated in a 0.5 microm silicon-on-sapphire complementary metal-oxide semiconductor. The VCSEL and photodetector devices are attached to the transceiver's integrated circuit by flip-chip bonding. A free-space optical link system is constructed to demonstrate correct dual-rate functionality. Experimental results show reliable link operation at 2 Gbit/s and 100 Mbit/s data transfer rates with approximately 104 and approximately 9 mW power consumption, respectively. The transceiver's switching time between these two data rates is demonstrated as 10 micros, which is limited by on-chip register reconfiguration time. Improvement of this switching time can be obtained by use of dedicated input-output pads for dual-rate control signals.     

Cyclic energy harvesting from pyroelectric materials

A method of continuously harvesting energy from pyroelectric materials is demonstrated using an innovative cyclic heating scheme. In traditional pyroelectric energy harvesting methods, static heating sources are used, and most of the available energy has to be harvested at once. A cyclic heating system is developed such that the temperature varies between hot and cold regions. Although the energy harvested during each period of the heating cycle is small, the accumulated total energy over time may exceed traditional methods. Three materials are studied: a commonly available soft lead zirconate titanate (PZT), a pre-stressed PZT composite, and single-crystal PMN-30PT. Radiation heating and natural cooling are used such that, at smaller cyclic frequencies, the temporal rate of change in temperature is large enough to produce high power densities. The maximum power density of 8.64 μW/cm3 is generated with a PMN-30PT single crystal at an angular velocity of 0.64 rad/s with a rate of 8.5°C/s. The pre-stressed PZT composite generated a power density of 6.31 μW/cm(3), which is 40% larger than the density of 4.48 μW/cm3 obtained from standard PZT.     

Automated crystal puller

Control circuits for pulling uniform cross section crystals from the melt are described. In the basic circuit, the output of a sensor that monitors an R.F. power source is compared to a reference voltage by a controller and the difference is used to adjust the current to a saturable core reactor that feeds a generator. In the present process this power stabilization method is converted to a rate of change of weight stabilization process by comparing the voltage output of an electronic balance; which weighs the pulling crucible, its contents and the pedestal on which it stands (1,2); to a generated voltage that varies linearly with time (3,4) and applying the difference in series with the reference voltage of the controller so that the temperature increases if the crystal weight increases too fast and decreases if it increases too slow. This unit, along with suitable automatic shutdown circuits, permits the full automation of crystal growth once seeding has been satisfactorily accomplished.     

基于霍尔效应的印刷机能耗检测方法研究

目的采用霍尔元件法搭建印刷机群能耗数字化检测平台。方法通过建立印刷机能耗指标模型框架体系,形成以总耗电量指标、均值类指标、耗电比例类指标等为主的印刷机耗电评价标准,完善能耗评价准则。采用灵敏度高、稳定性好的霍尔元件作为能耗检测元件,并分析霍尔效应、磁平衡式电流和电压霍尔传感器的检测电路。采用伏安法功率测量方式分别检测各负载电路的电流与电压,通过A/D转换模块实现检测数据数字化,并通过硬件控制核心对采集的数字信号进行运算、输出和显示,采用CAN总线实现硬件控制系统与上位机之间数字信息交互。结果搭建了印刷机群能耗数字化检测系统平台,实现了外围设备与上位机间的数据交互,实现了印刷机群以数据为核心,通过能耗检测、能效分析、能源成本控制以及能源指标优化,提高了能源利用效率。结论能耗检测的实现既能减少冗余电量损耗,又有利于监测电路稳定性,利用霍尔元件法实现印刷机群能耗检测的方法是可行的。