消除密勒电容实现光电耦合器快速工作的研究  

Research on Eliminating Miller Capacitance to Realize Fast Operation of Optocoupler

作　　者：崔建国 宁永香 Cui Jianguo;Ning Yongxiang(Shanxi Institute of Technology, Yangquan Shanxi 045000, China)

机构地区：[1]山西工程技术学院,山西阳泉045000

出　　处：《山西电子技术》2020年第4期91-93,共3页Shanxi Electronic Technology

摘　　要：普通光电耦合器由于存在密勒电容,故极易受密勒效应影响,造成数据传输的时效性较差,将光耦的光电三极管集成在一个级联电路中,级联电路包括共射极工作模式的光电管和共基极模式的晶体管T2,从T2角度看,晶体管T2工作于射极跟随器模式,T2基极电位稳定,故光电管集电极同样有稳定的直流电位,光电管电压放大倍数几乎为零,密勒电容被消除,光耦的工作频率加快。Because of Miller capacitance,ordinary photoelectric couplers are vulnerable to Miller effect,resulting in poor timeliness of data transmission.The photoelectric transistor of the photocoupler is integrated into a cascade circuit,which includes a common emitter mode phototransistor and a common base mode transistor T2.From the perspective of T2,crystals are formed.The T2 operates in emitter follower mode,and the T2 base potential is stable.Therefore,the collector of photocell also has a stable DC potential.The voltage amplification factor of the photocell is almost zero,Miller capacitance is eliminated,and the working frequency of the photocoupler is accelerated.

关 键 词：光电耦合器 相位 密勒电容 密勒效应 射极跟随器 

分 类 号：TP271[自动化与计算机技术—检测技术与自动化装置]