高稳定度电磁透镜电流源基准电阻的温度补偿

电流源的稳定度是影响高稳定度电磁透镜分辨率与成像质量的关键因素之一,而基准电阻作为电流源的反馈元件,其稳定度直接影响电流源的稳定度。为了提高基准电阻的稳定性,通过分析基准电阻与页温度系数(negative temperature coefficient, NTC)热敏电阻的温度特性,并提出了一种通过NTC热敏电阻对基准电阻进行温度补偿的电路结构。最后以Pt100电阻作为基准电阻,分析了该电路结构的性能。结果表明,与基准电阻相比,经补偿后所得到的等效基准电阻的稳定性提高了10倍以上。

Temperature Compensation of Reference Resistance of Current Source in High Stability Electromagnetic Lens

The stability of the current source is one of the key factors affecting the resolution and imaging quality of the high stability electromagnetic lens. As a feedback element of the current source, the stability of the reference resistance directly affects the stability of the current source. In order to improve the stability of the reference resistance, the temperature characteristics of the reference resistance and NTC (Negative Temperature Coefficient) thermistor are analyzed, and a circuit structure for temperature compensation of the reference resistance by NTC thermistor is proposed. Taking Pt100 resistance as the reference resistance, the performance of the circuit structure is analyzed. The results show that the stability of the equivalent reference resistance obtained by compensation is more than 10 times higher than that of the reference resistance.