加热电流对恒温晶振温度稳定性的影响

Effect of Heating Current on the Temperature Stability of Oven-Controlled Crystal Oscillators

通信技术的发展对恒温晶振的小型化需求越来越高。在设计一款小尺寸的恒温晶振时发现,环境温度从-40℃到85℃时,频率曲线一致向上,难以满足±3×10^(-9)频率温度稳定度要求。经分析表明,晶振的加热电流随环境温度而变化,在通过低电导率的接地引线时引起晶振PCB内的地电压波动,进而导致变容管的偏置电压发生变化。采用双地法和补偿法解决了加热电流引起的地电压波动对恒温晶振温度稳定性的影响。

The miniaturization of oven-controlled crystal oscillators(OCXO)is necessary for developing communication technology.When developing a small-sized OCXO,we found that frequency curves of the OCXO leaned upwards uniformly when ambient temperature increased from-40 to 85℃,failing to satisfy the requirement of±3×10^(-9).Variations in the heating current of the oscillator with temperature cause biasing voltage fluctuations in the variable diode when current flows through the ground pin made of metal with low conductivity.This problem was solved using the proposed dual ground pin and passive compensation methods.