基于LM2596芯片零起调直流稳压电源的设计

Design of DC power supply based on LM2596 chip with adjust from zero

设计一种中子管储存器用零起调降压型直流开关稳压电源。该电源采用BUCK拓扑结构,设计轨至轨LMV358运放电压反馈电路与LM2596内部误差放大器配合调节,克服LM2596降压芯片最低输出电压1.2 V的不足,实现从零起调。运放辅助电源电路采用12 V电源单独供电,其中运放输入端5 V和2.5 V基准电压源,由TL431可控精密稳压源电路构成。经实验测试,电源输入电压最高为45 V,输出电压实现从零起调,最高可调节到35 V,负载调整率为1.3%,最大输出电流能力为3 A,电源平均工作效率为93.44%,具有过载保护功能。

this paper designs a zero-voltage step-down DC switching regulator for a neutron tube accumulator. In order to achieve output voltage adjusting from zero,the power that adopts BUCK topology uses a rail-to-rail op amp to design a voltage feedback circuit to overcome the chip′s minimum output voltage of 1.2 V. The op amp′s auxiliary power supply uses a 12 V power supply. The 5 V and 2.5 V reference voltage input terminals of the op amp are designed by TL431,which is a kind of precision voltage regulator source. The test results show that input voltage of power is up to 45 V, the output voltage is achieved from 0 to 35 V,load regulation of power is 1.3%, output current capacity is 3 A,average efficiency of power is 90% and power includes overload protection.