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1、2020/8/14,电子信息工程专业英语教程,1,Unit 3 Electronic System Components,Lesson 8 Clock Sources 电子信息工程专业英语教程任治刚 主编 电子工业出版社 ,2020/8/14,电子信息工程专业英语教程,2,Lesson 8 Clock Sources,Backgrounds Text tour Language in use Vocabulary Structure Reading/writing techniques,2020/8/14,电子信息工程专业英语教程,3,Terminology Oscillator TCXO,
2、PLL, VCO Detector,Backgrounds,2020/8/14,电子信息工程专业英语教程,4,Terminology,2020/8/14,电子信息工程专业英语教程,5,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,Oscillator,2020/8/14,电子信息工程专业英语教程,6,TCXO: Temperature Compensated Crystal Oscillator 温度补偿晶体振荡器 PLL: Phase Lock
3、ed Loop 锁相环 VCO: Voltage Controlled Oscillator 压控振荡器,TCXO, PLL, VCO,2020/8/14,电子信息工程专业英语教程,7,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,Detector,2020/8/14,电子信息工程专业英语教程,8,Outline Clock Devices Crystals, Crystal Oscillators, Compensated Oscillators, Voltage Con
4、trolled Oscillator, Frequency Synthesizers, Clock Buffers Clock Parameters Clock Jitter, Skew, Tolerance/Accuracy, Stability, Aging, Slew, Duty Cycle,Text tour,2020/8/14,电子信息工程专业英语教程,9,A basic piezoelectric quartz crystal Two kinds of crystals Series Resonant Parallel Resonant,Clock DevicesCrystals,
5、2020/8/14,电子信息工程专业英语教程,10,An oscillator with the crystal as the feedback element Provides the most accurate and stable output frequency. The preferred clock source in most high-speed digital systems requiring clocks.,Clock DevicesCrystal Oscillators,2020/8/14,电子信息工程专业英语教程,11,Try to adjust the variat
6、ion in frequency due to temperature and voltage Temperature Compensating Oscillators (TCXO),Clock DevicesCompensated Oscillators,2020/8/14,电子信息工程专业英语教程,12,The output of VCO is controlled by a voltage control input pin.,Clock DevicesVoltage Controlled Oscillator,2020/8/14,电子信息工程专业英语教程,13,Use one or m
7、ore PLL to generate one to many different frequencies on their outputs, from one or more reference sources. A PLL has two inputs a reference input a feedback input. A PLL corrects frequency in two ways frequency correction Phase correction,Clock DevicesFrequency Synthesizers,2020/8/14,电子信息工程专业英语教程,1
8、4,Figure 3.4. Block Diagram of a Phase Locked Loop,Clock DevicesFrequency Synthesizers,2020/8/14,电子信息工程专业英语教程,15,A device in which the output waveform directly follows the input waveform. Have a propagation delay Skew will exist on the outputs,Clock DevicesClock Buffers,2020/8/14,电子信息工程专业英语教程,16,The
9、 deviations in a clocks output transitions from their ideal positions. Cycle-cycle jitter Period jitter Long-term jitter Causes of jitter Power supply noise The internal PLL of the synthesizer Random mechanical noise from vibrations of the crystal Random thermal noise from crystal, or any other reso
10、nating device.,Clock ParametersClock Jitter,2020/8/14,电子信息工程专业英语教程,17,The variation in arrival time of two signals specified to arrive at the same time Clock Driver Skew (Intrinsic Skew) Board Design Skew (Extrinsic skew),Clock ParametersSkew,2020/8/14,电子信息工程专业英语教程,18,A measure of how close the part
11、 operates to the specified (nominal) frequency, typically referenced at ambient temperature (25oC +/- 5oC).,Clock ParametersTolerance/Accuracy,2020/8/14,电子信息工程专业英语教程,19,A parameter usually associated with crystals and oscillators.,Clock ParametersStability,2020/8/14,电子信息工程专业英语教程,20,The systematic ch
12、ange in frequency over time due to internal changes in crystal/oscillator.,Clock ParametersAging,2020/8/14,电子信息工程专业英语教程,21,The rate of change of voltage or frequency,Clock ParametersSlew,2020/8/14,电子信息工程专业英语教程,22,The ratio of the output high time to the total cycle time.,Clock ParametersDuty Cycle,2
13、020/8/14,电子信息工程专业英语教程,23,Vocabulary Increment, propagation, deviation, transition, Intrinsic, extrinsic, nominal Structure Reading/writing techniques,Language in use,2020/8/14,电子信息工程专业英语教程,24,Vocabulary,2020/8/14,电子信息工程专业英语教程,25,Increment in dictionary,The process of increasing in number, size, quan
14、tity, or extent. 增加 Something added or gained: 增量 A slight, often barely perceptible augmentation. 微小增长 One of a series of regular additions or contributions: 累加 A small positive or negative change in the value of a variable. 变量增量,2020/8/14,电子信息工程专业英语教程,26,Increment in text,The Resolution will deter
15、mine in what size increments the frequency can change. 精度决定了频率改变的增量。,2020/8/14,电子信息工程专业英语教程,27,Increment in use,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,2020/8/14,电子信息工程专业英语教程,28,Propagation in dictionary,Multiplication or in
16、crease, 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,2020/8/14,电子信息工程专业英语教程,29,Propagation in text,A Clock Buffer is a device in which the output waveform directly follows the input waveform. The input waveform propagates through the devi
