基于LDO电荷泵的快速瞬态响应的DC-DC电源

DC-DC source with fast transient response based on LDO current pump

为了提高DC-DC电源的瞬态响应能力,提出一种新的电荷泵结构。该电荷泵由主开关电源模块和低压差稳压器(LDO)模块组成。主开关电源模块在稳态和瞬态响应时均处于工作状态;LDO模块由功率管、误差放大器和反馈环路组成,稳态时功率管关断,降低系统的功耗;当负载电流突然变化,引起输出电压变化时,LDO模块启动,其提供的充/放电电流达到理想值,使负载电流迅速恢复,将输出电压箝位在一个设定的阈值内。仿真结果表明,所提电荷泵在负载电流的变化较大时,可以很好地改善系统输出电压的瞬态响应,避免电压过冲。

A kind of current pump is proposed to improve the transient response of DC-DC source,which consists of the main SPS（Switching Power Supply） module and the LDO（Low DropOut regulator） module.The SPS works at both steady and transient states while the LDO,consisting of power tubes,error amplifiers and back-forward loop,turns its power tubes off at the steady state to reduce the power consumption and supplies ideal charge / discharge current to rapidly recover the load current and to clamp the output voltage variation below the threshold value when the output voltage varies due to the load current change.Simulative results show that the proposed current pump enhances the transient response of DC-DC source and suppresses the output voltage overshoot excellently when the load current changes greatly.