VC-TCXO TEST CIRCUIT
关于VC-TCXO压控温补晶振20.000MHz DSA321SDA规格参数，晶诺威科技介绍如下：
VC-TCXO压控温补晶振20MHz关键参数：
- 标称频率：20.000MHz
- 封装尺寸：DSA321SDA/VC-TCXO3225
- 供电电压：3.3V
- 温度频差：±0.5PPM
- 工作温度范围：-40~+85℃
- 压控特性：Vcont=1.5V±1.0V(±9PPM~±15PPM)
VC-TCXO压控温补晶振20MHz电气参数详情如下：
Notes：
1、 Clipped sine wave (DC-coupled) 输出波形：削峰正弦波
TA=+25°C 常温+25℃
2、 Please leave after reflow in 2h or more at room ambient.回流焊之后放置至少两个小时以上
3、 Positive slope (Frequency becomes high in proportion to frequency control voltage.)正斜率（频率与频率控制电压成正比）
Outline, Pin Connections VC-TCXO压控温补晶振20MHz尺寸及引脚说明
What is a voltage controlled temperature compensated crystal oscillator?
Temperature Compensated Crystal Oscillators (TCXOs) deliver excellent temperature characteristics combined with low power consumption and fast warmup. Voltage Controlled Temperature Compensated Crystal Oscillators (VC-TCXOs) combine the same excellent temperature characteristics, low power consumption and fast warmup with a voltage control function to allow precise tuning of the output frequency after PCB assembly.
Voltage control can also be used during operational life, to compensate for any effects of aging as well as offering the ability to pull back to nominal frequency where there is a change of circuit conditions. TCXOs and VC-TCXOs are used where the stability of a standard Crystal Clock Oscillator is insufficient.