LDO稳压器中动态频率补偿和限流保护的研究  

Research on the dynamic frequency compensation and overcurrent protection scheme for the LDO regulator

作　　者：王晓娟[1] 王炜[1] 刘涛[1] 

机构地区：[1]合肥工业大学电气与自动化工程学院,安徽合肥230009

出　　处：《合肥工业大学学报（自然科学版）》2007年第5期549-553,共5页Journal of Hefei University of Technology：Natural Science

基　　金：国家自然科学基金资助项目(60373076);国家自然科学基金资助项目(60576034)

摘　　要：.文章针对LDO稳定性的问题,提出了一种内部动态频率补偿电路,使LDO线性稳压器的稳定性不受负载电容的等效串联电阻的影响,其单位增益带宽也不随负载电流变化而改变,大大提高了瞬态响应特性;采用Hynix 0.5μm CMOS工艺模型对电路进行仿真;此外,该电路在实现动态频率补偿的基础上又加入了系统的过流保护功能,当负载电流大于限制电流时,LDO不能正常工作;当负载电流小于限制电流时,又自动恢复到正常工作状态。The paper presents an interior dynamic frequency compensation circuit to solve the stability problem of the low dropout（LDO） regulator. This compensation circuit can make the stability of the LDO linear regulator undependent on the effect of load capacitor＇s equivalent serial resistance（ESR）, and it also makes the unit gain frequency bandwidth change slightly when the load is varying, thus greatly improving the performance of transient response. Furthermore, on the basis of dynamic frequency compensation, an overcurrent protection circuit is designed. When the load current is greater than the current-limit value, the LDO regulator can not work, but if the load current is smaller than the current-limit value, it can work again. The design is implemented by the Hynix 0. 5μm CMOS process technology.

关 键 词：LDO 动态频率补偿 等效串联电阻 过流保护 

分 类 号：TN43[电子电信—微电子学与固体电子学]