Design of a High-precision Wide-range Constant-current Source
Maocheng Wu · Electrical Measurement & Instrumentation · 2011
A wide-range high-precision constant-current source is presented,which is mainly comprised of a voltage reference,some operational amplifiers and a darlington transistor.The range of the circuitry's output current value is from 1μA to 1A.The working principle of the designed constant-current circuitry is analyzed in details and deduced mathematically,and the selective rules of the practical elements are illuminated.The performance of the designed constant-current source is tested,and the results indicate that the circuitry could generate a high-precision steady current.The maximal relative error of precision and maximal error of stability of the output current are 0.152% and 0.047% respectively.