Design Consideration of a High Precision and Stability Linear Current Source

In this paper, the design considerations of a high precision and stability linear current source is presented. Firstly, to evaluate the precision, low-frequency equivalent circuit of the single linear current path is established and the strict output current equation is derived accordingly. Sensitivity analysis is also conducted to identify how much variations in the values for each parameter will impact the results for the output current. Secondly, to evaluate the stability, high-frequency equivalent circuit is established at the same time and compensation network is composed consequently. A RL parallel damping filter is also added to improve the performance of PSRR of the linear unit. Finally, computer simulations results are shown close agreement between modelled estimates and simulated values. Monte Carlo simulation is also used during the analysis and simulations by varying all of the parameter values with respect to tolerance and distribution type to identify the worst case precision values in real applications.