一种具有快速恢复能力的过流保护电路设计  

Design of overcurrent protection circuit with fast recovery capability

作　　者：晁慧 陈思宁 陈海进[1,3] CHAO Hui;CHEN Sining;CHEN Haijin(School of Microelectronics(School of Integrated Circuits),Nantong University,Nantong 226001,Jiangsu Province,China;ATEKON Corporation,Nanjing 210012,China;Provincial University Key Laboratory of Semiconductor Devices and Integrated Circuit Design and Testing,Nantong 226001,Jiangsu Province,China)

机构地区：[1]南通大学微电子学院(集成电路学院),江苏南通226001 [2]傲拓科技股份有限公司,江苏南京210012 [3]半导体器件与集成电路设计封测省高校重点实验室,江苏南通226001

出　　处：《电子元件与材料》2025年第1期63-70,共8页Electronic Components And Materials

基　　金：江苏省科技成果转化资金重大项目(BA2022001)。

摘　　要：为了减小过流对电路的损害,设计了一种用于纹波电压二次方恒定导通时间(V2 COT)控制的降压(BUCK)转换器的过流保护电路。通过调整纹波注入电路的输出波形,延长其输出信号小于反馈电压信号的时间,推迟导通信号的到来,从而降低系统开关频率。采用0.18μm的BCD(Bipolar-CMOS-DMOS)工艺完成了电路设计和仿真验证。结果表明,当限流阈值为3.9 A时,开关频率最低降为正常工作时的四分之一,相应的占空比最低为0.02。在-20~85℃的温度范围内,限流阈值最大变化了0.88%,故障排除后,恢复时间为18μs。本电路结构简单、恢复时间短,改善了传统过流保护方案恢复时间长的问题。To reduce the damage of overcurrent,a protection circuit by constant-on-time V2(V2 COT)controlled buck converter was designed.By adjusting the output waveform of the ripple injection circuit,the duration of the output signal less than feedback voltage was extended,thereby the system switching frequency was reducd.The circuit was designed and verified using 0.18μm Bipolar-CMOS-DMOS(BCD)process.The results show that the switching frequency is reduced to as low as one quarter of the normal operation when the current-limiting threshold is 3.9 A,and the corresponding duty cycle is as low as 0.02.Over the temperature range of-20-85℃,the current-limiting threshold varies with the maximum of 0.88%,and the recovery time is 18μs after troubleshooting.This circuit has a simple structure and a short recovery time,thus addressing the problem of the prolonged recovery commonly encountered in traditional overcurrent protection methods.

关 键 词：过流保护 逐周期限流 开关频率 快恢复 

分 类 号：TN433[电子电信—微电子学与固体电子学]