Design of a High Precision Current Source

摘要：

Current source is one of the key components in electrical measurement and control systems. However,the noise introduced by temperature drift and other interference makes it a significant source of systematic errors. To develop a high precision and stable current source,a Howland-based voltage to current conversion (V/I) circuit is presented in this paper. The current source is fully programmable using a DSP via RS-232 interface. Moreover,a sampling circuit is provided,using the sampling results,calibration is made to further reduce the output error of the current source. Under a constant 140 Ω load,experiment results shows that current output ranges from-50mA to +50mA with error less than 3μA,and features low temperature drift and distortion. This proves that such design can be an effective way to provide a precise and stable range output current.

关键词： current source Howland calibration.

作者: Yu Peng Yanchao Xia Shaojun Wang

作者单位: Harbin Institute of Technology NO.92 West Da-zhi Street Harbin,150001,China

会议类型: 国际会议

会议名称: 2009 9th International Conference on Electronic Measurement & Instruments(第九届电子测量与仪器国际会议 ICEMI2009)

会议地点: 北京

会议语种:英文

页码: 1065-1069

在线出版日期: 2009-08-16（万方平台首次上网日期，不代表论文的发表时间）