童诗白模拟电子技术基础第四版第六章

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1、Rb2Rc+VccuiT+-+-uoC1+C2Rb1ReCeRLRbRc+VccuiT+_+_uoC1RL+_+_C2CEQQCiUIT0 u时，)(ECiIIT 0u时时，)(EBBEUUUEeEIRUBCII阻容耦合共射放大电路阻容耦合共射放大电路RbRc+VccuiT+_+_uoC1RL+_+_C2_阻容耦合共集放大电路阻容耦合共集放大电路RbRs+VccuiT+_+_uoC1RL+_+C2us+_Re具有射极电阻的共射电路具有射极电阻的共射电路Rb2Rc+VccuiT+-uoC1+C2Rb1ReRL 直接耦合两级放大电路直接耦合两级放大电路Rb2Rc1+VccuiT1+-+-uoRb1

2、Rc2T2Re2 直接耦合两级放大电路直接耦合两级放大电路Rb2Rc1+VccuiT1+-+-uoRb1Rc2T2Re2Rf AuOuIDZUZR1R2RUREFuO AuOuI-+A1R2-+A2uOR3R4uO1uIR1+R1R2R3R4uiu0+R1R2RLR3ui+u0Rf+ufIifiiX0XiXfX对地电压对地电压iiXX iXXi+uf+R1R2RLR3ui+u0Rf+duIifidi(a)(b)iuu d)(fiduuu Idii)(fIdiii +R1R2R3R4uiu0uO-+AuIR2R1-+AuIuOR2R1C-+AuIuOR2R1C；则为电压反馈则为电压反馈若若,0

3、x ,0u f0 令。则则为为电电流流反反馈馈若若,0 x ,0u f0 +R1R2RLR3ui+u0Rf(a)(b)图图（a）中中 0u0 uf0 ，则图图（b）中中 0i0 uf0 ，则+uffio41341fuRRRRRu/Ioof33fIRRRIIo+R1R2R3R4uiu0-+A1R2-+A2uOR3R4uO1uIR1ud+-uf+iifR1+VCCuiT1+-C1R2R3+-uoC2T2R4R5R6C3+uf+VCCfIT1+-C1Rc1Re1+-C3T2Re2Rc2RfC2RRs+-usuIuOoIiI6262负反馈放大电路的四种基本组态负反馈放大电路的四种基本组态-+AuiuO

4、R2R1RLuduf-+usRs+-0u0RLR+-0u当当RL0L0L0uRRRu0211fuRRRu )(fiduuu，越小，越小，sisuuRu0uf 0u反馈越明显；反馈越明显；+R1RsRLR3us+u0RfridIiIfI00I0RLR0I0L000IRRRI当当RL0f33fIRRRI )(fidIII，时时 当当0R s 一定，反馈越明显;一定，反馈越明显;iI。越大，反馈越明显越大，反馈越明显sRdIfI0I 0IidsdruI -+R2RfuoR1Rc+VccuiT-+R2RfuoR1Rc+VccuiT-+R2RfuoR1Rc+VccuiTRe-+R2RfuoR1Rc+Vc

5、cuiTRe6363负反馈放大电路方块图及一般表达式负反馈放大电路方块图及一般表达式iXiXfXoXAF fiiXXX ioXXA ofXXF ifXXFA iofXXAFAA1iiiXFAXXA fioXXXF1AFAAf1fAAFFAAAf1，时时 当当 1 FA1 A Af，时时 当当0 FA1 。时时，即即0X0 X 0i反反馈馈深深度度 FA1 1 FA1 当当FA1AAf ioXXA iofXXAA Af负反馈负反馈，时时 当当 1 FA1 正反馈正反馈 Af,自激振荡自激振荡F1FAAiUfUiUoUuuAuuF+-+-+-RLoIiUfUiUoUiuAuiF+-+-+-RLiI