unit3-4

Unit3 Historically, the linear regulator was the primary method of creating a regulated output voltage. It operates by reducing a higher input voltage down to the lower output voltage by linearly controlling the conductivity of a series pass power device in response to changes in its load. This results in a large voltage being placed across the pass unit with the load current flowing through it. 在历史上，线性稳压器曾是产生稳压输出电压的主要方法。通过对级联功率通过器件导电性线性控制以响应负载变化，线性稳压器将输入高电压降为输出低电压。这种方法导致在负载电流流经的通过单元两端出现一个大电压。 admissible load 容许载重 capacitive load 电容性负载 circuit load 电路 模拟电路李宁答案12数字电路仿真实验电路与电子学第1章单片机复位电路图组合逻辑电路课后答案 负荷, 线路负荷 inductive load 电感负载 ohmic load 电阻负载 output load 输出负载 safe load 安全载荷 unmatched load 不匹配负载 The switching regulator operates the power devices in the full-on and cutoff states. This then results in either large currents being passed through the power devices with a low “on’’ voltage or no current flowing with high voltage across the device. 开关电源中的功率器件工作在全开和截断状态。这样，要么在大电流流经功率器件时，导通电压很低；要么在大电压时，没有电流通过器件。 current-gain cutoff 电流增益截止 grid-current cutoff 栅流截止 grid-voltage cutoff 栅压截止 During the “on” period, energy is being stored within the core material of the inductor in the form of flux. There is sufficient energy stored to carry the requirements of the load during the next off period. 在“接通”周期，能量以磁通的形式存储在电感的铁芯材料中。存储的能量足以满足负载在下一个“断开”周期的需求。 acidic flux 酸性熔(焊)剂 battery flux 蓄电池流出量 core flux 铁心通量 magnetic flux 磁通量 non-oxygen flux 无氧焊剂 rosin flux 焊剂 scalar flux 标量通量 short-circuit flux 短路磁通, 短路通量 Non-isolated switching power supplies are typically used for board-level regulation where a dielectric barrier is provided elsewhere within the system. 非隔离开关电源的典型应用为具备绝缘隔板的系统提供板级电压调理。 air barrier 气密层; 内衬层 collector barrier 集电极势垒 contact (potential) barrier 接触势垒 customs barrier 关税壁垒 emitter barrier 发射极势垒 fire barriers 防火间隔 language barrier 语言障碍 sonic barrier 音障, 声垒 water barrier 防水层 The companies building their own power systems are leaning toward transformer isolation in as many power supplies as possible since it prevents a domino effect during failure conditions 制造自己系统电源的公司倾向于在尽可能多的电源中采用变压器隔离，因为这种隔离避免了故障出现时将产生的连锁反应。 A mode or state of being: 状态或状况： A state of readiness or physical fitness. 生理状况 A disease or physical ailment: 疾病或身体不适 Social position; rank. 社会地位；身份 One that is indispensable to the appearance or occurrence of another; prerequisite: 先决条件 One that restricts or modifies another; a qualification. 限定条件 Existing circumstances 存在的环境 Conditions in the office made concentration impossible. 办公室的状况根本不可能使人专心 A crowbar is a latching SCR which is fired when the output is sensed as entering an overvoltage condition. 短路器是一个自锁的半导体可控整流器。当输出进入过电压状态，就会激发这个整流器。 abnormal operating conditions 不正常的工作情况 adverse conditions 不利条件， 有害状态 housing conditions 居住条件 normal running conditions 正常工作［运行］状态 oscillating condition 振荡条件 short-circuit condition 短路状态 Oscillator 振荡器 Resonant 谐振的 Series Resonant 串联谐振 Parallel Resonant 并联谐振 Resonating frequency 谐振频率 TCXO: Temperature Compensated Crystal Oscillator 温度补偿晶体振荡器 PLL: Phase Locked Loop 锁相环 VCO: Voltage Controlled Oscillator 压控振荡器 Detector detector n.检测器，检波器，探测元件 phase detector n.鉴相器, 相位检测器 frequency detector n.鉴频器, 频率检测器 The Resolution will determine in what size increments the frequency can change. 精度决定了频率改变的增量。 angle increment 角增量 annual increment 年增量 average increment 平均增量 frequency increment 频率增量 logarithmic increment 对数增量 Propagation in dictionary Multiplication or increase, as by natural reproduction. 繁殖 The process of spreading to a larger area or greater number; dissemination.蔓延；散发 The act or process of propagating, especially the process by which a disturbance, such as the motion of electromagnetic or sound waves, is transmitted through a medium such as air or water. 传播 A Clock Buffer is a device in which the output waveform directly follows the input waveform. The input waveform propagates through the device and is redriven by the output buffers. Hence, such devices have a propagation delay associated with them. In addition, due to the differences between the propagation delay through the device on each input-output path, skew will exist on the outputs. 时钟缓冲器是一种输出波形直接跟随输入波形的器件。输入波形通过该器件并被输出缓冲器重新驱动。因此，该类器件存在传播延迟。此外，由于在每个输入-输出通道间存在传播延迟的差别，输出端将出现相位抖动。 beyond-the-horizon propagation 超越地平线传播, 超视距传播 carry propagation 进位传送 earth-layer propagation 地层传播 error propagation 误差传播 forward-scatter propagation 前向散射传播 free space propagation 自由空间传播 ground wave propagation 地波传播 high-frequency propagation 高频传播 microwave propagation 微波传播 multipath propagation 多径传播 radio propagation 无线电波传播 ultrasonic propagation 超声波传播 Deviation in dictionary The act of deviating or turning aside. 背离，偏离 An abnormality; a departure: 反常；偏移： Deviant behavior or attitudes. 不正常的行为或态度 The difference, especially the absolute difference, between one number in a set and the mean of the set. 偏差 Jitter can be defined as the deviations in a clock’s output transitions from their ideal positions. The deviation can either be leading or lagging the ideal position. 抖动被定义为时钟输出的状态转换位置偏离了理想位置。这种偏离可能超前于理想位置，也可能滞后于理想位置。 absolute deviation 绝对差 random deviation 随机偏差 second order deviation 二阶方差 system deviation 系统偏差 Transition in dictionary The switching from one state (e.g., positive voltage) to another (negative) in a serial transmission. A change from one significant condition to another in a telegraph or a data signal. Period jitter, also called short-term jitter, is a change in a clock’s output transition from its ideal position over consecutive clock edges. 周期内抖动也称为短期抖动。它是指在相继时钟边沿的范围内时钟输出状态转换位置偏离理想位置。 black-to-white transition 黑白过渡 coaxial-to-waveguide transition 同轴线-波导管过渡 environmental transition 环境变迁 flip-flop transition 触发器状态转换 Intrinsic： Of or relating to the essential nature of a thing; inherent. 本质的；固有的 The intrinsic value of a coin is the value of the metal it is made of. Extrinsic： Not forming an essential or inherent part of a thing; extraneous. 非本质的，无关系的 That's something extrinsic to the subject. Originating from the outside; external. 外来的；外部的 Clock Driver Skew (Intrinsic Skew) is the amount of skew caused by the clock driver itself. 时钟驱动器相位偏移（内部相位偏移）是由时钟驱动器引起的相位偏移量。 Board Design Skew (Extrinsic skew) is the amount of skew caused by board layout issues such as: 电路板 设计 领导形象设计圆作业设计ao工艺污水处理厂设计附属工程施工组织设计清扫机器人结构设计 相位偏移（外部相位偏移）是由下列电路板布线问 题 快递公司问题件快递公司问题件货款处理关于圆的周长面积重点题型关于解方程组的题及答案关于南海问题 造成的相位偏移量： Nominal in dictionary Assigned to or bearing a person's name 提名的，记名的 Existing in name only 名义上的 Insignificantly small; trifling 微不足道的 Of, relating to, or being the amount or face value of a sum of money or a stock certificate, for example, and not the purchasing power or market value 面值的 According to plan or design 按计划进行的，设计的，标称的 Tolerance/Accuracy/Precision is a measure of how close the part operates to the specified (nominal) frequency, typically referenced at ambient temperature (25oC +/- 5oC). 该参数度量的是器件的工作频率和标称频率（一般是指在常温下）的接近程度。 nominal chairman 名义主席 a nominal list of the children 所有孩子的名单 a nominal par 票面价格 nominal horse power 标称[公称, 额定]马力 a nominal register 名册 nominal damages 象征性赔偿 Food is supplied at a nominal cost. 廉价供应食物。 Everything was nominal during the test. 试验中一切进行顺利。 VSWR Voltage Standing Wave Ratio 电压驻波比 Frequency response 频率响应 Decibel (dB) decibel 分贝 A unit used to express relative difference in power or intensity, usually between two acoustic or electric signals, equal to ten times the common logarithm of the ratio of the two levels. Pad 焊点，焊盘 Lead 引线 ribbon cable 带状电缆 扁平柔性电缆 BNC 同轴电缆卡环形接头 Interconnect devices must meet certain performance requirements in most or all of the following categories: Signal integrity Power loss … 互连器件必须满足下列大多数或者全部性能要求： 信号完整性 功率损耗 … absorption loss 吸收损耗 antenna loss 天线损耗 aperture loss 孔径失真 conduction loss 传导损耗 contact loss 接触损耗 conversion loss 变换损耗 coupling loss 耦合损耗 crosstalk loss 串话损耗 distribution loss 配电损耗 gross loss 毛损, 总损 harmonic loss 谐波损耗 insertion loss 插损 iron core loss 铁芯损耗 load loss 负载损耗 power mismatch loss 输入失配损耗 propagation (power) loss 传播(功率)损耗 transmission loss 传输损耗 arc shield 电弧罩 baffle shield 隔音板 cable shield 电缆套管 electrostatic shield 静电屏蔽 ground shield 接地屏蔽 radiation shield 防辐射屏蔽 Causing damage or harm; injurious. 引起损害的；有害的 An interconnect that must pass the short rise time of a high-speed signal pulse can be detrimental to maintaining signal integrity due to an unwanted reflection. 因为出现了反射，所以在通过互连路径传送高速信号脉冲时，短促的上升时间就会破坏信号的完整性。 The act or process of degrading. 降级 The state of being degraded; degeneration. 堕落，衰退 A decline to a lower condition, quality, or level. 退化，下降 Decomposition of a compound by stages, exhibiting well-defined intermediate products. 降解 In data communications, a deterioration in the characteristics of a signal for whatever reason. A condition in which the system operates at reduced levels of service. These circumstances are usually caused by unavailability of various equipment units or subsystems. Signal integrity is defined by loss of quality of the input signal. Ideally, the signal at the output of an interconnect should be equal in all characteristics with the signal at the input of the interconnect. In reality, signal degradation occurs. 信号完整性是指输入信号质量的损失。理想情况下，互连器件的输出端信号和输入端信号在所有特性上都完全相同。实际中会发生信号质量的下降。 Relation in degree or number between two similar things. 比率 The relation between two quantities expressed as the quotient of one divided by the other: 比例 The ratio of 7 to 4 is written 7:4 or 7/4. Tests that indicate signal integrity include: Voltage standing wave ratio (VSWR) Frequency response Rise-time of signal edges Current flow 能够反映信号完整性的测试有： 电压驻波比 频率响应 信号边沿的上升时间 电流 abundance ratio 丰度 amplification ratio 放大率 aspect ratio 长宽比; 纵横比 availability ratio 可用率; 利用率; 资用率 energy efficiency ratio 能量效率比 faculty-student ratio 师生比 limit ratio 限幅比 power standing wave ratio 功率驻波比 signal-noise ratio 信噪比 base station 基站 mobile station 移动站 A dial is… A graduated surface or face on which a measurement, such as speed, is indicated by a moving needle or pointer. 标度盘 The face of a clock. 钟 表 关于同志近三年现实表现材料材料类招标技术评分表图表与交易pdf视力表打印pdf用图表说话 pdf 针盘 A sundial. 日晷 The panel or face on a radio or television receiver on which the frequencies or channels are indicated. 调谐度盘 A movable control knob or other device on a radio or television receiver used to change the frequency. 调谐钮 A rotatable disk on a telephone with numbers and letters, used to signal the number to which a call is made. 电话拨号盘 Antenna 天线 A metallic apparatus for sending or receiving electromagnetic waves. also called aerial packet-switching 包交换，分组交换 A packet is … A sequence of binary digits including data and call control signals that is switched as a composite whole. The data, call control signals, and possibly error control information, are arranged in a specific format. A short block of data of fixed length and destination information. It is the unit in which information (a message) is transferred in a packet-switching network. Packets may consist of as many as 8000 bits, and more from node to node in the network. MTSO: Mobile Telephone Switching Office移动电话交换局 MSC: Mobile Switching Center 移动交换中心 PSTN: Public Switched Telephone Network 公共交换电话网 A second area where the U.S. and Europe differed is in the humble matter of phone numbers. 美国和欧洲另一个不同之处在于“电话号码”这件小事上。 Consequently, the usual rule of ‘‘caller pays’’ also applies to mobile phones in Europe (except for international calls where costs are split). 这样，“主叫付费” 的常规也可以应用于欧洲的移动电话（费用分开的国际电话除外）。 Such systems, known as push-to-talk systems, were installed in several cities beginning in the late 1950s. 20世纪50年代末，有几个城市开始架设这样的系统（被称之为“按下－通话系统”) Also, due to the large power of the hilltop transmitter, adjacent systems had to be several hundred kilometers apart to avoid interference. 此外，位于山顶上的发射机功率很大。为了避免互相干扰，临近系统间必须距离几百公里。 The key idea that gives cellular systems far more capacity than previous systems is the use of relatively small cells and the reuse of transmission frequencies in nearby (but not adjacent) cells. “采用较小蜂窝”和 “发射频率重用” 使蜂窝系统获得了比以往系统大得多的容量。 “发射频率重用” 是在附近小区中，而不是在相邻小区中。 Thus, the cellular design increases the system capacity by at least an order of magnitude, more as the cells get smaller. 这样，蜂窝设计将系统容量至少提高了一个数量级；而且蜂窝越小，提高量越大。 The MTSOs (Mobile Telephone Switching Office) communicate with the base stations, each other, and the PSTN (Public Switched Telephone Network ) using a packet-switching network. 移动电话交换局使用分组交换网络和基站、其他的移动电话交换局及公共服务电话网进行通信。 On a D-AMPS mobile phone, the voice signal picked up by the microphone is digitized and compressed using a model that is more sophisticated than the delta modulation and predictive encoding schemes. 在D-AMPS 移动电话上，语音信号由麦克风拾取之后，先进行数字化，然后使用比增量调制和预测编码更复杂的模型进行压缩。 To a first approximation, GSM is similar to D-AMPS. Both are cellular systems. 乍一看，GSM 和D-AMPS很相似。两者都是蜂窝系统. With mobile telephony there is a huge gain from doing digitization and compression in the handset, so much so that in D-AMPS, three users can share a single frequency pair using time division multiplexing. 对于移动电话而言，在电话机内完成数字化并进行数据压缩有很大好处——这样一来，3个D-AMPS用户可以通过时分复用共用一对频率。 Theoretically, 992 channels can be supported in each cell, but many of them are not available, to avoid frequency conflicts with neighboring cells. 理论上讲，每个蜂窝小区可以支持992个信道；但为了避免和邻近蜂窝小区发生频率冲突，许多信道并不能使用。 TDM is comparable to the people being in the middle of the room but taking turns speaking. FDM is comparable to the people being in widely separated clumps, each clump holding its own conversation at the same time as, but still independent of, the others. CDMA is comparable to everybody being in the middle of the room talking at once, but with each pair in a different language. Thus, the key to CDMA is to be able to extract the desired signal while rejecting everything else as random noise. 因此，CDMA的关键在于能够提取出希望得到的信号，而把其他信号当作随机噪声而加以抑制。 Each station is assigned a unique m-bit code called a chip sequence. To transmit a 1 bit, a station sends its chip sequence. To transmit a 0 bit, it sends the one’s complement of its chip sequence. 每个（移动）站分配到唯一的一个称为“码片序列”的m位码。要传送比特“1”，就发送这个码片序列；要传送比特“0”，就发送这个码片序列的反码。 A good heuristic here is for each mobile station to transmit to the base station at the inverse of the power level it receives from the base station. 一个很好的思路是：每个移动站向基站发送信号的功率是接收到的基站信号功率电平的倒数。 Increasing the amount of information to be sent from b bits/sec to mb chips/sec can only be done if the bandwidth available is increased by a factor of m, making CDMA a form of spread spectrum communication (assuming no changes in the modulation or encoding techniques). 只要可用带宽提高至原来的m倍，就可以将发送信息量从b 位/秒提高到mb码片/秒；这使得CDMA是一种扩频通信的形式（假定调制和编码技术没有发生变化的话）。 In principle, given enough computing capacity, the receiver can listen to all the senders at once by running the decoding algorithm for each of them in parallel. 从理论上讲，假如具备足够的计算能力，通过并行运行解码算法，接收机就能同时听到每一个发送方。 Nevertheless, CDMA is a clever scheme that is being rapidly introduced for wireless mobile communication. 但不管怎么说，CDMA是一种非常精巧的设计，并迅速地应用于无线移动通信中。 CDMA also has many other complicating factors that have been glossed over here. 在这里，我们尚未谈到CDMA技术中许多其他的、令问题复杂化的因素。 CPU The microprocessor "brain" of the computer system is called the central processing unit. Everything that a computer does is overseen by the CPU. Caching - The storing of frequently used data in extremely fast RAM that connects directly to the CPU Virtual memory - Space on a hard disk used to temporarily store data and swap it in and out of RAM as needed IDE Controller Integrated Drive Electronics (IDE) Controller - This is the primary interface for the hard drive, CD-ROM and floppy disk drive. PCI Peripheral Component Interconnect (PCI) Bus - The most common way to connect additional components to the computer, PCI uses a series of slots on the motherboard that PCI cards plug into. The appliances in our homes have microprocessors built into them, as do our televisions. Even our cars have a computer. 电视机等家用电器内部就有微处理器，汽车里也有计算机。 Virtual memory - Space on a hard disk used to temporarily store data and swap it in and out of RAM as needed 虚拟存储器：用于暂存数据和在需要时和RAM交换数据的硬盘空间。 Power supply - An electrical transformer regulates the electricity used by the computer. 电源：一种为计算机提供电能的电源管理器。 User Interface - Providing a way for you to communicate and interact with the computer 用户接口：提供人机通信和交互的途径。