Design of digital control direct circuit current source in high accuracy and wide range
XU Ke-qiang · Journal of Chongqing Technology and Business University · 2006
A digital control direct circuit current source of high accuracy and wide range is designed by using SPCE061A micro control unit(MCU).In hardware design,D/A converters output of SPCE061A MCU is adapted to control the circuit current source of being voltage-controlled.The output current is transformed into the voltage by sample resistant and the voltage is sent to A/D converter,the voltage being compared with the setting current.If there exist errors,we should adapt D/A converter output,so the output current of the current source of being voltage-controlled is changed,and the actual current value is the same with the setting value.In software design,the closed loop control and PID arithmetic is used to realize high precision and wide range output current.The maximum of the current source is 200 mA,the single step precision is higher than 0.2 mA.