NKG频率控制产品的技术资料
BACKGROUND ON QUARTZ CRYSTALS – 石英晶体的背景资料
First used in 1918 as a piezoelectric element in an oscillator.
Piezoelectric from Greek meaning “pressure electric”.
Material is SiO2 Silicon Oxide.
Low intrinsic losses (High Q).
Easily processed, low cost.
Easy to grow in large quantities, high purity and perfection.
首次在1918年作为压电元件用在振荡器中.
Piezoelectric来自希腊语,意思是“压电的”.
材料是SiO2, 二氧化硅.
内在损耗低 (高Q值).
容易加工,成本低
容易大量生产,纯度高
QUARTZ CRYSTAL OSCILLATORS – 石英晶体振荡器
Main Functions and Advantages are:
Precision Timing – Excellent Frequency Source.
Accurate Reference for Reception and Carrier Signalfor Data Transmission.
High Frequency stability VS Time and Temperature.
Low Phase Noise / Jitter.
主要功能和优点是:
精确计时--- 极好的频率源.
是接收和传送信号的精确参考.
高频率稳定性VS时间和温度.
低相位噪声/抖动
QUARTZ CRYSTAL OSCILLATORS – 石英晶体振荡器
Disadvantages are:
Susceptible at certain cases to severe mechanical stress.
(Shock and Vibrations)
1 – Degrades the phase Noise
2 – Poor Short Term Stability
Low Pullability in comparison to VCO.
缺点是:
在某些情况下易受严重机械应力的影响(冲击和震动).
1-降低相位噪声.
2-短期温度性差.
与VCO相比牵引差.
APPLICATIONS – 运用
所有基于微处理器的系统
TTL、CMOS、HCMOS、ACMOS、ECL逻辑兼容
计算机和外围设备,主机架、个人电脑、笔记本电脑、工作站、调制解调器、驱动器、附加卡、键盘
消费品,无绳,移动电话,寻呼机,掌上电脑,传真,机顶盒,玩具,电视,收音机
电信,中央办公室、高级台式机、数字多路复用设备、局域网
射频通信设备,FM/蜂窝应用,移动和基站设备,无线应用
频率敏感仪表,频率计数器,信号发生器,频谱分析仪,自动测试设备,
示波器、射频报警和POS系统、数据交换、过程控制仪表
军用/商用,导航、测距设备、军事通信、制导
CRYSTAL IS THE HEART –石英晶振晶体就是心脏
MECHANICAL EQUIVALENT ILLUSTRATION – 机械等效图解
The mechanical model consists of a Spring, a Mass and a Damping Element.
The equivalent electrical circuit is a series branch of a Capacitor,a Inductor and a Resistor.
机械模式包括一个弹簧,一个质量和一个阻尼元件.
等效电路是一个电容器,一个电感器和一个电阻器的串联.
EQUIVALENT CIRCUIT – 等效电路
The symbol of a Quartz Crystal Y1 and the Load Capacitor CL.
石英晶体Y1和负载电容CL的标志.
The Equivalent Circuit of a Crystal consists of a series branch of capacitor C1,inductance L1 and resistor
R1 with the shunt capacitor C0 in parallel.
石英晶体的等效电路包括由电容C1, 电感L1, 电阻R1组成的串联支路, 其与静态电容C0并联.
CRYSTAL‘S SPECTRAL RESPONSE – 晶体的光谱反应
In parallel mode a capacitor is used to adjust frequency.
In series mode it requires additional inductance to calibrate down capacitance.
在并联模式中使用电容来调整频率.
在串联模式中需要另外的电感来校低电容.
DIFFERENT QUARTZ SHEAR MODES – 不同的石英切变模式
AT–CUT ANGLE VS TEMPERATURE BEHAVIOR – AT切角度VS温度表现
AT–CUT TEMPERATURE CHARACTERISTIC – AT切温度特性
Factors that affect behavior:
Fundamental or Overtone used
Geometry of plates
Size, shape, thickness,density and stress of electrodes
Drive level
Impurities and strains in quartz material
Rate of temperature change
影响表现的因素.
使用基频或泛音
晶片几何
尺寸,形状
激励电平
杂质
温度变化速度
CRYSTAL VOCABULARY – 晶体词汇
Frequency:
Number of waves or cycles per second that the quartz crystal vibrates or oscillates.
Normally assign in MHz or kHz at 25 C.
Frequency Tolerance:
The allowed deviation in PPM from the nominal frequency at 25degC.
Specify in Part Per Million (ppm)
Stability over temperature:
The allowed deviation in PPM between a lower and higher temperature.
频率:石英晶体一秒内振动或震荡波或循环的次数. 一般用
25度时MHz或kHz表示。
调整频差:与25度时的标称频率之间允许的偏差PPM值.
温度频差: 高低温之间允许的偏差PPM值
CRYSTAL VOCABULARY – 晶体词汇
Aging:
Cumulative change in frequency over time. Specified in PPM per year.
Load Capacitance:
Dynamic or effective capacitance of the complete circuit as measured across thecrystal terminals. The load capacitance must be specified when the crystal is operatingin a parallel resonant (anti resonant) circuit.
Series Resonance:
When a crystal operates at series resonance it appears resistive in the circuit and itsimpedance is near zero. The load capacitance is not required.
老化:随着时间频率的累计变化。以PPM/年定义。
负载电容:从晶体引脚量测的完整电路的动态或有效电容。
当晶体工作在并联谐振(反谐振)电路中时必须定义负载。
串联谐振:当晶体串联谐振工作时,他在电路中显示出有阻抗
的,而且其阻抗接近0。负载是不需要的。
CRYSTAL VOCABULARY – 晶体词汇
Equivalent Series Resistance (ESR):
The internal or equivalent resistance of the circuit measured at the series resonant frequency. Lower frequencies have higher ESR values.
Drive Level:
The level of power or current in the crystal during operation.
Mode of Oscillation:
A crystal can work at many frequencies, either on its FUNDAMENTAL frequency or
one of the odd OVERTONES, it must be specified because it has to match with oscillator design.
ESR:在串联谐振频率测量时的电路内部或等效电阻。频率越低ESR越高.
激励电平:晶体工作时的功率或电流电平.
振荡模式:晶体可以以很多频率工作,或是基频频率或是某个奇数泛音,必须进行定义,因为它必须与振荡器的设计相符.