The design adopts self-designed high accurate voltage source, Micro Control Unit
(MCU), D/A converter and amplifier to control the on-state of Power MOS FET, to attain constant current. The closed loop system realizes constant current output of high-precision, presettable and step-by-step adjustable, and its output current data can be directly displayed by digital devices.
Finally achieve a high-precision constant current source by locking output with closed hardware loop, closed software loop, software real-time integrating, real-time filtering. The role of software is to compensate the temperature variance of sampling resistances by data segment interpolation, while the linear interpolation compensation is applied to intersegments, which improves the output precision further. It has advantages on high precision, simple construction, performance stable, easy operation, low cost and loaded capability.