一种高摆幅软启动线性稳压源设计

Design of high-swing input LDO with soft-start circuit

基于0.5μm工艺设计一种带软启动电路大摆幅输入电压的线性稳压源（LDO）,为解决高电压输入时LDO输出节点的瞬态过冲电流问题,设计一种在缓冲器的输出端加入MOS开关的软启动方案,提高电路的安全可靠性。通过仿真分析,结果表明该电路在输入电压10~40 V变化,其线性调整度为7.5 m V@30 V,输出5 V稳定电压,负载电流范围0~10 m A,输出电流1~10 m A,瞬态变化时负载调整度为12 m V@9 m A。电源电压上电时间为1 ms时,LDO的输出过充电流不超过6 m A。

A high-swing input LDO with soft-start circuit in 0.5 μm process was presented. For reducing the rush-in current at output of LDO to increase reliability about LDO, a method of soft-start which added a CMOS switch at output of buffer was proposed. The line regulation of LDO was 7.5 m V@30 V（input voltage was 10~40 V）, and output voltage was 5 V. The output range of current was 0~10 m A, load regulation was 12 m V when output current change from 1~10 m A in 10 ns.When supply voltage start rised to 40 V in 1 ms, the output current of LDO was under 6 m A.