关于有源晶振的参数规格，大部分采购可能只认识比较主要的封装尺寸，类型，频率，精度，电源电压之类的，但其实振荡器详细的参数并止这些。而是多达十几种甚至是二十几种，VCXO是压控晶体振荡器的英文简称，具有电压控制性能，因此被命名为压控晶振，适合用到无线通信，飞机船舶，工业仪器仪表，军用，全球导航定位系统，智能手机等产品。以下是VCXO晶振相关的详细的参数及其含义。

PPM：“百万分率”的缩写，一种用于指定允许值的计算方法，晶体或石英晶体振荡器的频率偏差。也可以被视为“ppm”。
相位噪声：一个相位调制边带的功率密度与总信号之比。目录中的所有相位噪声数据归一化为一赫兹等效带宽。
负载（扇出）：振荡器驱动其他设备的容量。 TTL器件以可驱动的门数指定;即10个TTL门。 CMOS输出以pF指定;即15 pF或50 pF负载。
启用/禁用：启用/禁用引脚类似于开/关开关。启用/禁用时为低电平或逻辑0会导致设备不振荡。使能/禁止引脚上的“高电平”或逻辑1允许单元正常工作（使能），产生指定的输出。
偏差：数量与其名义价值的差异。出于目的，频率与标称频率或指定频率不同的量。
下降时间：信号从逻辑'1'变为逻辑'0'所需的时间。
频率范围：晶振可以制造的频率范围，对规格的影响最小。
线性度：偏离控制电压与输出频率的直线关系。
振荡器：在其输出端产生特定频率的交流电的电路或设备。
老化：振荡器输出频率的系统平均变化仅作为时间的函数。老龄化不包括环境变化的影响。
可移动性：压控晶体振荡器的频移是控制电压的函数。
上升时间：信号从逻辑'0'变为逻辑'1'所需的时间。
稳定性：由温度变化引起的振荡器频率的变化，以所需的振荡器频率为参考。
启动：从瞬时电压施加到振荡器的时间，直到振荡器输出稳定。
预热：振荡器频率在几小时后稳定在给定的频率容差范围内所需的时间。
三态：三态选项类似于启用/禁用。当pin1上有一个“逻辑1”（例如5 Vdc）时，该单元正常工作“启用”，产生指定的输出（例如TTL）。当引脚被禁止时，“逻辑0”（ex 0 Vdc）进入高阻抗或三态模式。三态模式允许客户从电路中移除石英振荡器而无需将其物理移除。用于调整，测试或解决他们的电路板问题。
对称性：信号处于逻辑高电平的每个周期的百分比。该参数在指定的电压阈值或输出波形幅度的百分比下测量。
英文版：
Aging: A systematic average change of an oscillator’s output frequency as a function only of time. Aging does not include effects of changing environments.
Deviation: The amount by which a quantity differs from its nominal value. For purposes, the amount by which a frequency differs from the nominal or specified frequency.
Enable/Disable: The enable/disable pin is similar to an on/off switch. A low or logic 0 on the enable/disable causes the unit not to oscillate. A “high” or logic 1 on the enable/disable pin allows the unit to work as normal (enabled) producing the specified output.
Fall Time: the time required for a signal to go from Logic ‘1’ to logic ‘0’.
Frequency Range: The range of frequencies over which an oscillator can be fabricated with minimal impact on specifications.
Linearity: The departure from a straight line relationship of control voltage to output frequency.
Oscillator: A circuit or device that produces an alternating current of a specific frequency at its output terminals.
Phase Noise: The ratio of the power density of one phase modulation sideband to the total signal. All phase noise data in the catalog are normalized to a one Hertz equivalent bandwidth.
Load (Fan out): The capacity of the oscillator to drive other devices. TTL devices are specified in the number of gates that can be driven; i.e., 10 TTL gates. CMOS outputs are specified in pF; i.e. 15 pF or 50 pF loads.
PPM: The abbreviation for “Parts Per Million,” a method of calculation used to specify the permissible
frequency deviation of a crystal or oscillator. May also be seen as “ppm”.
Pullability: The frequency shift of a VCXO as a function of control voltage.
Rise Time: The time required for a signal to go from Logic ‘0’ to logic ‘1’.
Stability: The change in oscillator frequency, referenced to the desired oscillator frequency, caused by temperature change.
Start-Up: The period from the instant voltage is applied to the oscillator until the oscillator output is stabilized.
Symmetry: The percentage of each period that a signal is in logic high. This parameter is measured at a specified voltage threshold or at a percentage of the output waveform amplitude.
Tri-state: The tri-state option is similar to the Enable/Disable. When you have a “logic 1” (ex 5 Vdc) on pin1,the unit works as normal “enabled” producing the specified output (ex TTL). When the pin is disabled, “logic 0” (ex 0 Vdc) it goes into high impedance or tristate mode. The tristate mode allows the customer to remove the oscillator from their circuit without physically removing it. Useful for tuning, testing or trouble shooting their board.
Warm-Up: The time required for an oscillator’s frequency to settle to within a given tolerance of the frequency several hours later.

正在载入评论数据...

上一篇：欧美晶振的层次定义与结构介绍

下一篇：贴片振荡器回流焊后的滞后效应

此文关键字：有源晶振 VCXO晶振维管晶振

姓名：
邮箱：
正文：

资讯中心

金洛博客

中英文精简版有源晶振参数词汇表

相关资讯