A kind of switch current source with high order LC filter output

摘要

a kind of switch current source with feedback loop compensation is presented in this paper to solve the problem that switching current source can not be applied in high-precision circuit. A good tradeoff has been made by this type of switch current source in improving the dynamic response and reducing low ripple. At the beginning of the paper, the model of BUCK-type circuit is built after analyzing the circuit. Next, the main factor which affects the stability of the system, the filter, is emphasized. The contradiction of high out band rejection and high stability which exists in LC filter is pointed out. To solve this problem, the program of feedback loop compensation is proposed; to verify this program the simulation result is presented. Finally, the implementation circuit of switch current source with high order LC filter output is presented.