LecturaBJTs-Polarizacion
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Transcript of LecturaBJTs-Polarizacion
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8/18/2019 LecturaBJTs-Polarizacion
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446 Chapter 6 Bipolar Junction Transistors (BJTs)
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6.7 Biasing in BJT Amplifier Circuits
!"#$%& ()*+$,+ )-, #".$/*( 0/%1$&*.")$/%( /1 234 "567$1$,.(8 9, %/9 "++.,(( )-, $56/.)"%):*,()$/% /1 ;$"($%& "%+ $)( .,7")$/%(-$6 )/ (5"77 )9/ /;#$/*(
".."%&,5,%)( "., $%& &//+= L$.()8 ")),56)$%& )/ ;$"( )-, 234 ;> 1$A$%& )-, #/7)"&, ' (# ;>8 1/.
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" #$";7, "66./"0-O 4-, #,.> (-".6 ,A6/%,%)$"7 .,7")$/%(-$6 !" @v (# 5,"%( )-") "%> (5"77 "%+
$%,#$)";7, +$11,.,%0,( $% ' (# 1./5 )-, +,($.,+ #"7*, 9$77 .,(*7) $% 7".&, +$11,.,%0,( $% ) " "%+$% ' "# = C,0/%+8 ;$"($%& )-, 234 ;> ,()";7$(-$%& " 0/%()"%) 0*..,%) $% )-, ;"(,8 "( (-/9% $%
L$&= D=MNB;F8 9-,., $( "7(/ %/) " .,0/55,%+,+ "66./"0-= !,., )-,
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TABLE 6.5 Characteristics of BJT Amplifiers"# %# &
'())(*
+),--+. /0,1! 2!345
'())(*+),--+. 6,-7
/0,1! 2!385
'())(* %"9+
/0,1! 2!3:5
;),--+.
* 0(. -7+ ,*-+.?.+-"-,(* (P( )/ 2PGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGG
@
+2
β >P( ) / 2 +2P( ) 3 , +"
> 3 , +2PGGGGGGGGGGGGGGGGGGGGG@ +"
3 , +" + 7||( )@
> 3 , +2PGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGG
α +" + 7||
/ 2 +2PGGGGGGGGGGGGGGGGGG@
β +" + 7||
+9,1 β >P( ) / 2 +2P( )PGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGG@
/ 2 3 , +" +" 3 , +" + 7||( )
α +" + 7||
/ 2GGGGGGGGGGGGGGGGGG
α +" + 7||
+9,1 / 2PGGGGGGGGGGGGGGGGGGG
β >P( ) / 2 + 7P( ) / 2 + 7
+ 7 / 2PGGGGGGGGGGGGGGGG + 7
+ 7 / 2 +9,1 β >P( ) ⁄ P PGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGG
6v% >Q
+(F- / 2 +9,1 β >PGGGGGGGGGGGGPQ
∞
) ( ' "" 4!H@( ) + (# ⁄ (
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6.7 Biasing in BJT Amplifier Circuits 44
SN
>B[=-7(F17 .+@F&,*1 + # .+9-(.+9 ) # -( -7+ @+9,1* O"=F+ (< S 5? # ,- @(+9 *(- 9(=O+ -7+ ?.(%=+) (< -7+@+?+*@+*&+ (< -7+ O"=F+ ( )/ (,, 1./5 )-, ";/#, ,:*"<)$/% )-") " ($567, 9"> )/ .,()/., ) # )/ $)( %/5$%"7 #"7*, 9/*7+ ;, )/ .,+*0, + # 1./5 W=W U Ω ;> )-, 5"&%$<
)*+, /1 )-, (,0/%+ ),.5 $% )-, +,%/5$%")/. BR=TDI U ΩF= 4-*( " 5/., (*$)";7, #"7*, 1/. + # $% )-$( 0"(,
9/*7+ ;, + # = W U Ω8 9-$0- .,(*7)( $% ) # = S=RS 5? S 5?=SN
G) (-/*7+ ;, %/),+ )-") $1 9, "., 9$77$%& )/ +."9 " -$&-,. 0*..,%) 1./5 )-, 6/9,. (*667> "%+ )/ "00,6)
" 7/9,. $%6*) .,($()"%0, 1/. )-, "567$1$,.8 )-,% 9, 5"> *(, " #/7)"&,8 )/ ) # B$=,=8
S 5?F8 .,(*7)$%& $% +S = ^ U Ω "%+ +T = E U Ω= ], (-"77 .,1,. )/ )-, 0$.0*$) *($%& )-,(, 7")),. #"7*,( "(
+,($&% T8 1/. 9-$0- )-, "0)*"7 #"7*, /1 ) # *($%& )-, $%$)$"7 #"7*, /1 + # /1 W=W U Ω 9$77 ;,
' ( +A ]=
' # A ' (# :!: ]@=
+ # ' # ) # GGGGGG
:!:
>GGGGGGG :!: J Ω= = =
4!> ) # 4!> >× 4!> )[!= =
+> +8+ >8
4!>GGGGGGG >84 J Ω= =
+8 +> +8+GGGGGGGGGGGGGGGGGG' "" A ]=
) # A 4!H@
:!: J Ω( ) Y4 ̂ ^ A4( ) J Ω( )
>4>GGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGG+
GGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGG 4!B: )[= =
) # A 4!H@
:!: 4!48H+GGGGGGGGGGGGGGGGGGGGGGGGGGG 4!BB > )[= =
Example 6.20
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450 Chapter 6 Bipolar Junction Transistors (BJTs)
6.7.2 A Two-Power-Supply Version of the ClassicalBias Arrangement
? (/5,9-") ($567,. ;$"( ".."%&,5,%) $( 6/(($;7, $1 )9/ 6/9,. (*667$,( "., "#"$7";7,8 "(
(-/9% $% L$&= D=DS= ].$)$%& " 7//6 ,:*")$/% 1/. )-, 7//6 7";,7,+ Y &$#,(
BD=SRIF
Example 6.20 continued
G% )-$( 0"(,8 +,($&% T8 9, %,,+ %/) 0-"%&, )-, #"7*, /1 + # =
0,*"==I# -7+ O"=F+ (× 4!BB )[ > )[= =
+" >8 Y@
>GGGGGGGGGGGGGGG A J Ω= =
6.47 0(. @+9,1* > ,* ;Q")?=+ 2!84# &"=&F="-+ -7+ +Q?+&-+@ ."*1+ (4` ."*1+R +( ) ⁄ +GGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGG=
Figure 6.61 D,"9,*1 -7+ DEC F9,*1 -6( ?(6+. 9F??=,+9! _+9,9-(. + ( ,9*++@+@ (*=I ,< -7+ 9,1*"= ,9 -( %+ &"?"&,-,O+=I &(F?=+@ -( -7+ %"9+! N-7+.G
6,9+# -7+ %"9+ &"* %+ &(**+&-+@ @,.+&-=I -( 1.(F*@# (. -( " 1.(F*@+@ 9,1*"=
9(F.&+# .+9F=-,*1 ,* "=)(9- -(-"= β G,*@+?+*@+*&+ (< -7+ %,"9 &F..+*-!
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6.7 Biasing in BJT Amplifier Circuits 4
4-$( ,:*")$/% $( $+,%)$0"7 )/ a:= BD=SREF ,A0,6) 1/. ' ## .,67"0$%& ' ((= 4-*( )-, )9/ 0/%()."$%)(
/1 a:(= BD=SRMF "%+ BD=SRDF "667> -,., "( 9,77= `/), )-") $1 )-, )."%($()/. $( )/ ;, *(,+ 9$)- )-,
;"(, &./*%+,+ B$=,=8 $% )-, 0/55/% ,9 -( %+ F9+@
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452 Chapter 6 Bipolar Junction Transistors (BJTs)
G) $( $%),.,()$%& )/ %/), )-") )-$( ,:*")$/% $( $+,%)$0"7 )/ a:= BD=SRNF8 9-$0- &/#,.%( )-, /6,.")$/%
/1 )-, )."+$)$/%"7 ;$"( 0$.0*$)8 ,A0,6) )-") ' "" .,67"0,( ' (( "%+ +" .,67"0,( + # = G) 1/77/9( )-") )/
/;)"$% " #"7*, /1 ) # )-") $( $%(,%($)$#, )/ #".$")$/% /1 β 8 9, (,7,0) `/),8-/9,#,.8 )-") )-, #"7*, /1 + ( +,),.5$%,( )-, "77/9";7, %,&")$#, ($&%"7 (9$%& ") )-, 0/77,0)/.
($%0,
BD=SRNF
6.7.4 Biasing Using a Constant-Current Source
4-, 234 0"% ;, ;$"(,+ *($%& " 0/%()"%) "11,0)$%& ;$"( ()";$7$)>= L*.)-,.8 0*..,%)