直流放大器

?±?÷·??ó?÷ ?±?÷·??ó?÷????·??ó?±?÷?????ò±????????????????÷???????ü??·???????×?????????±í????????×????÷????×????????÷???????????±?÷·??ó???·?????????±?÷·??ó?÷?????????±?÷·??ó?÷???÷?????±?÷·??ó?÷???? ???????????±?÷·??ó?÷ ???????±?÷·??ó?÷?è???????????±?÷?????????????????????¨a???????·????????×èRe2????BG2?????????????ú×??±?÷???????????ó?¨????Ube2=Uc1-Ue2).?????¨b)?????·??????D1?°D2×÷????????????BG2??BG3????????????????·?±???Ube2=0.3·ü??Ube3=0.45·ü??D3??±??¤×÷????±?????BG1?ù?????????ó??·??????????°???????????÷???ó???????????à?????ó???????????è???????????¨???????ú???è????????×÷????????C?????·?????????ó??Rc1??Rc2???á?????????????????????°?ó???±?÷????????????????D?????·??????PNP?¨BG1??BG3??
??NPN?¨BG2?????????à·???????????????????BG1?????????÷??BG2?????????÷??BG2?????????÷??BG2?????????÷??BG3???????÷???????????????????????????????????·??×??ó?±?????????????ó?? ???????????±?÷·??ó?÷ ??2?¨a)?????????±?÷·??ó???·?????????????ü????BG1??BG2?????????à?????§????×é???????????·????????????????????????????±???Ui1??Ui2??????????????·?±???Uc1??Uc2????????????UC1??UC2????????UO=UC1-UC2O???????·?????????????? 1?????????????????????? ???????·???????????à???????·???????????ù???±?????????±?????????????????÷?????????ù???????????÷IC1=?÷IC20????????????UO=?÷IC1RC-?÷IC2RC=0???ù???????????????????? 2???????????±??????????·??ó???? ?¨??°?·ù???à?????à???à?????????????????????????????????????????·??A???????±Ui1=Ui2?±?????????????????ò????????Uo=KUil-KUi2=0, 3???????????±??????·??ó???? ?¨??°?·ù???à?????à???à·????????????????????????????????±Ui1=-Ui2?????????±??????????????????????·?±???Uc1=-KUi1??Uc2=-KUi2???ù????????·??ó±???Kud: Kud=(Uc1-Uc2)/(Ui1-Ui2)=(-Ui1K-Ui1K)/2Ui1=-K=(-)(hfeRc)/(Rs+hie) ???????????·?????????????????????????????ù±?????????·??ó???·?à????±????ù??????·??ó±???Kud?????????????·??·??ó±????à?? ???á????????????????????????·??ó±?????????????????·??ó±??????ó???????ò??????????
????±?CMRR*=Kud/Kuc×÷??????????·??ó???·????????????????±ê?? ??2 4?????????¨?????¤×÷???????? ??2?¨a)??????????×èRe???????????°?????????ù??????????·???×÷???????????????????±??Ic1??Ic2?
????±?????????ú?ú??????·????????? ?á????IC1??IC2??????±????à??????????????Re??×????÷×÷???????????¨?????¤×÷????????Re???ó?????÷×÷???????ó???????????????????????????????¨?ú??????????Re??????????????????????????????????????????????×?????????????????????Re??????·???×÷?????ò?????ü???á??????????????·??ó±????? ±í?? ?????????¨??2????????·??ó?÷??±???
??·¨ ???????????????????¨a?? ???????????????????¨b?? ???????????????????¨C?? ??????????????????(d) ????·??ó±??? Kud=-?¨??Rc/Rs+rbe) Kud=-?¨??Rc/Rs+rbe) Kud=-[??Rc/2(Rs+rbe)] Kud=-[??Rc/2(Rs+rbe)]
????·??ó±??? Kuc?ú0 ???? ???? Kuc?ú0 ????????±? ???? ?? ?? ???? ????????×è?? Rid=2(Rs+rbe) Rid=2(Rs+rbe) Rid=2(Rs+rbe) Rid=2(Rs+rbe) ????????×è?? Rod=2Rc Rod=2Rc Rod=2Rc Rod=2Rc ???? ???????à??·??ó????????????????
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