摘要
针对采用高端功率MOSFET的导通电阻作电流取样电阻的同步整流电流模式降压DC-DC变换器,设计了一种新型高精度斜坡补偿电路。该电路采用有一定死区时间的同步整流,防止主功率管和续流管同时导通。死区过后,主功率管给电感充电,此时,续流管漏极寄生电容还在放电,造成电流采样误差。针对该问题,提出一种斜坡补偿电路,进行误差消除设计。电路实现形式简单,斜坡的斜率可以灵活调节。
A new ramp compensation circuit with high-accuracy was designed for synchronous rectification current mode step-down DC-DC converter,in which main switch on-resistance was used as current sensing resistor.To prevent simultaneous conduction of main switch and synchronous switch,a certain amount of dead time was adopted,after which the inductor would be charged immediately.At this point,the synchronous switch also discharged its drain parasitic capacitance,which resulted in current sensing error.The novel ramp compensation circuit,which was designed to solve the problem,is easy to implement,and the slope was flexibly adjustable.
出处
《微电子学》
CAS
CSCD
北大核心
2011年第3期393-396,共4页
Microelectronics
关键词
同步整流
电流取样
电流模式
斜坡补偿
Synchronous rectification
Current sensing
Current mode
Ramp compensation
