高精度宽范围数控直流电流源设计

采用SPCE061A单片机,设计了一个高精度宽范围的数控直流电流源。硬件部分通过SPCE061A单片机的D/A输出控制压控电流源,该电流源的实际输出电流通过采样电阻转换成电压送A/D转换器,并与预设值进行比较;若有误差再调整D/A转换器的输出,从而改变压控电流源的输出电流,使该电流输出值与预设值相等。软件部分通过闭环控制、PID算法以实现高精度、高量程的电流输出。电流源输出电流最大值200 mA,电流步进精度>0.2 mA。

Design of digital control direct circuit current source in high accuracy and wide range

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.