Page 189 - 30105-2003 การวิเคราะห์วงจรอิเล็กทรอนิกส์ความถี่สูง
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181
                     4.





                                            r bb′  C =  C b e ′ +  C b c ′  (1 g R+  m out )  R out
                                                   T
                                                   r b e ′  V b e ′  g V
                                                                   m b e ′
                                                                                   I    D 1
                                                                                    1 d  r
                                                                                         1 d
                                              C T                        D 2
                              E g
                                                                                                π
                                π
                              π
                             ( -2 )                         R E                            V  ( o π − 2 )

                                   1     4.12  . %     4==D	ก (.  5 -  	
   0 %% 	  1 #   1     4.5



                                                            r bb′  R FH  1  R FH
                                                         B
                                                                  R FH  2
                                                                     r b e ′
                                                 R g
                                                       R BB                     C
                                                E                                T
                                                 g
                                                                 β +
                                                                ( F  ) 1 R E

                                                           R ≈  R EP  ≈  R EP 1
                                                            E

                                                 1     4.13 . % ก	   (
	   	 R
                                                                            FH

                     *&          4.18      (
	   	 F #       .5(  	
    1  +%    	
	       	
    2
                                                H
                                                        1
                       +  ,    	ก 
ก	  (4.21)         F =
                                                H
                                                    2 Rπ  FH  C T
                                                      ( 75 8.432 10 3 ) (   +     ×  3 )
                                                                     +
                                                                ×
                                                         ×
                                                                       2 75 8.432 10
                     $%          R FH 1  =  ( {  R    R BB  ) r+  bb′ } =               = 76.338 Ω
                                                               ( 75 8.432 10 3 )
                                       g
                                                                  +
                                                                         ×
                                    R  =  r  + ( β +  ) 1 R =  461.981+ (101 560×  ) 57.021 k=  Ω
                              FH 2  b e ′  F     E
                                                          ×
                                                                 ×
                                     R FH 1 FH 2    76.338 57.021 10 3   76.235 Ω
                                          R
                                    R  =         =                     =
                              FH                )
                                                                 ×
                                                          +
                                   ( R FH 1  +  R FH 2  ( 76.338 57.021 10 3 )
                                                       (
                                                                     ×
                                                             ×
                                                                3
                                        r +
                                    R C  ( d  R L )  560 4.762 10 +  56 10 3 )
                                    R  =  1      =                          = 554.886 Ω
                              out              ) (               3       3 )
                                    R +
                                                             ×
                                                                      ×
                                                       +
                                         d
                                   ( C  r +  R L   560 4.762 10 +   56 10
                                          1
                                                         I C dc  5.563 10 − 3
                                                                      ×
                                                           ( )
                                   C b c ′  = C =  C ob  = 1.3 pF, g =  =   = 216.459 mS;
                                                    m
                                    re
                                                                      ×
                                                        (k T q )  25.7 10 − 3
                                                          B
                                                        ×
                                    g m          216.459 10 − 3         − 12
                                                                    ×
                             C b e ′  =  −  C b c ′  =          − 1.3 10   = 113.593 pF
                                    π
                                   2 F           ×    ×    ×   6
                                      T         2 3.14 300 10
                                    C =  C  +  C  (1 g R+  )
                              T    b e ′  b c ′  m out
                             C =  113.593 10 − 12  + 1.3 10 − 12 { 1+ ( 216.459 10 − 3  ×  554.886 )}  =  271.036 pF
                                                   ×
                                         ×
                                                                     ×
                              T
                                                                                  ก         	
    
    ก  
  ก
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