一种nA级精密微电流源

A Precision Micro-Current Source with Nanoamp Output

针对微电流测量仪表的测试与校准,设计一种高精度的微电流源。该电流源基于单片机的数控结构,采用微电流电路的设计方法,实现了0~200 n A的微电流输出。本文对电压/电流（V/I）转换电路的温度漂移特性进行分析,并提出V/I转换电路的软件校准方法。测试表明,经过校准后的n A级微电流源性能稳定,精度较高,输出电流误差小于±0.01%FS（满量程）。

A precision micro-current source is designed for the test and calibration of micro-ammeters. It is based on the digitally controlled structure of mlcrocontroller system and uses the circuit design method for the micro-current situation to achieve a micro-current output with the range of 0-200.0nA. The temperature drift analysis and the software calibration method for the V/I convert circuit are discussed. The test shows that the calibrated micro-current source can work steadily with a high precision and the error less than ±0.01%FS.