【摘要】 首先根据四探针测试理论,阐述了恒流源电路在四探针测试仪中的重要性,给出了对恒流源的基本要求。然后介绍了我们在开发前期实验过的2种恒流源电路,它们分别是级联型镜象电流源电路和电压-电流转换电路。最后介绍了我们实际采用的直接利用反馈运放输出恒流的电路。对每种电路都给出了原理图、电流计算公式和性能分析。更多还原

【Abstract】 At first, according to the theory of four-point probe, the importance of the constant current source circuit in a four-point probe instrument is demonstrated. The requirements of the constant current source are listed. Then two circuits having been tested by us during our former developing course are elaborated. They are the cascaded mirror-image current source, the voltage-current transforming circuit. Finally, the utilized circuit with a feedback amplifier to output constant current is demonstrated. The graphs of principle, the formulas to calculate the current and the analysis of their performance are all illustrated. At last, the experience of us is summarized.更多还原