电子技术（非电类）课后习题答案rbe?300??(1??)
2)等效电路如题3-12解图所示26V
?0.97kΩICQ
??I?r?(1??)I?R??UibbebE????I?(R//R)U
o
b
C
B2
所以????Au
(RC//RB2)5//3.9
??40??17.3??rbe?(1??)RE0.97?41?0.1
题3-12解图3)??]?75//5.07?4.75kΩRi?RB1//[rbe?(1??)RE
Ro?RB2//RC?2.19kΩ图3-49题3-12图?。Ri,Ro,Au解3-13两级阻容耦合放大电路如图3-50所示，晶体管的?1??2???100，计算UB1Q?IE1QR224
UCC??20?3.87V
R2?R124?100
UB1Q?UBE3.87?0.7?IC1Q???0.62mARE15.1第11页共102页电子技术（非电类）课后习题答案rbe1?300??(1??)
UB2Q?
26V26
?300?101??4.535kΩIE1Q0.62
rbe2输入电阻输出电阻R46.8UCC??20?3.42V
R3?R46.8?33
UB2Q?UBE3.42?0.7
IE2Q?IC2Q???1.36mA
RE2226V26?300??(1??)?300?101??2.23kΩIE2Q1.36Ri?Ri1?R1//R2//rbe1?3.67kΩRo?RC2?7.5kΩ
Ri2?R3//R4//rbe2?1.59kΩ
????RC1//Ri2??10015//1.59??31.7Au1
rbe14.535
????RC2//RL??1007.5//5??134.5Au2
rbe22.23??A?A?总电压放大倍数Auu1u2?4263.65
图3-50题3-13图3-14在如图3-51所示电路中，晶体管的rbe1?0.6kΩ，rbe2?1.8kΩ。1）画出放大电路的微变等效电路；?；2）求电压放大倍数Au
3）求输入电阻Ri，输出电阻Ro。4）如将两级对调，在求2）、3）项并比较两结果。第12页共102页电子技术（非电类）课后习题答案图3-51题3-14图解1)微变等效电路如题3-14解图（a）所示。题3-14解图（a）2)??RE//RB2//rbe2?1.12kΩRL
???(1??)RLA?0.98u1
?rbe1?(1??)RL????(RC2//RL)??66.67Au2
rbe2
??A?A???65.34A
u
u1
u2
3)?]?120//46.52?33.52kΩRi?RB1//[rbe1?(1??)RL
Ro?RC2?3kΩ
4)两级对调后微变等效电路如题3-14解图（b）所示。Ri2?RB1//[rbe1?(1??)(RE//RL)]?48.92kΩ????(RC2//Ri2)??40?6//48.92??118.8Au1
rbe21.8??Au2
(1??)(RE//RL)
?0.99
rbe1?(1??)(RE//RL)
第13页共102页电子技术（非电类）课后习题答案题3-14解图（b）总电压放大倍数输入电阻输出电阻??A?A?Auu1u2??117.6
Ri?Ri1?RB2//rbe2?300//1.8?1.79kΩ
rbe1?(RC2//RB1)0.6?6//120
?3//?0.14kΩ
1??41
Ro?RE//
3-15两级放大电路如图3-52所示，晶体管的?1??2???40，rbe1?1.37kΩ，rbe2?0.89kΩ。1）画出直流通路，并计算各级的静态值（计算UCE1时可忽略IB2）；2）画出放大电路的微变等效电路；?,A?,A?。3）求电压放大倍数Au1u2u
图3-52题3-15图解1)直流通路如题3-15解图（a）所示第14页共102页电子技术（非电类）课后习题答案IC1Q?IE1Q
RB18.2
UCC??20?3.98V
RB1?RB28.2?33
IC1Q0.97U?0.73.98?0.7
?B1??0.97mAIB1Q???0.024mA
???RE1?RE13?0.39?40
UB1Q?
?1?RE?2)?7VUCE1Q?UCC?IC1Q(RC1?RE
题3-15解图（a）直流通路UB2Q?UC1?UCC?IC1QRC1?10.3VIC2Q?IE2Q?IB2Q?UCE2Q
IC2Q
UB2Q?0.7RE2?
?1.88mA
1.88
?0.047mA
?40
?UCC?IC2QRE2?10.412V
2)微变等效电路如题3-15解图（b）所示题3-15解图（b）微变等效电路3)Ri2?rbe2?(1??)(RE2//RL)?0.89?41?2.55?105.44kΩ
第15页共102页
电子技术 非电类 课后习题答案 荣雅君主编 - 图文
