BENEMÉRITA UNIVERSIDAD AUTÓNOMA DE PUEBLA
FACULTAD DE CIENCIAS DE LA ELECTRÓNICA
AMPLIFICADOR DIFERENCIAL CON BJT REPORTE DE LA PRÁCTICA N° 7
RESUMEN
Verificar a! carac"er#!"ica! $%!ica! &e '( a)*ifica&+r BJT, ………………………………………………………………………………………………
1
OBJETIVOS 1- Me&ir e *'("+ &e +*eraci.( e( D,C, /"+&a! a! c+rrie("e! 0 "+&+! +! +"a2e!-, 3- Me&ir a 4a(a(cia &ifere(cia, 5- Me&ir a 4a(a(cia e( (+&+ c+)6(, - Cac'ar a reaci.( &e rec8a9+ e( (+&+ c+)6( /RRNC-, ………………………………………………
E "ra(!i!"+r &e '(i.( $i*+ar /&e i(4:! $i*+ar 2'(c"i+( "ra(!i!"+r; + !'! !i4a! BJTe! '( &i!*+!i"i+ eec"r.(ic+ &e e!"a&+ !.i&+ c+(!i!"e("e e( &+! '(i+(e! PN )'0 cerca(a! e("re !#; <'e *er)i"e c+("r+ar e *a!+ &e a c+rrie("e a "ra:! &e !'! "er)i(ae!, U( "ra(!i!"+r &e '(i.( $i*+ar e!"% f+r)a&+ *+r &+! U(i+(e! PN e( '( !++ cri!"a !e)ic+(&'c"+r; !e*ara&+! *+r '(a re4i.( )'0 e!"rec8a, De e!"a )a(era <'e&a( f+r)a&a! "re! re4i+(e!=
MARCO TEORICO
TRANSISTOR BJT
E)i!+r; <'e !e &ifere(cia &e a! +"ra! &+! *+r e!"ar f'er"e)e("e &+*a&a; c+)*+r"%(&+!e c+)+ '( )e"a, S' (+)$re !e &e$e a <'e e!"a "er)i(a f'(ci+(a c+)+ e)i!+r &e *+r"a&+re! &e car4a,
Ba!e; a i("er)e&ia; )'0 e!"rec8a; <'e !e*ara e e)i!+r &e c+ec"+r,
C+ec"+r; &e e>"e(!i.( )'c8+ )a0+r,
AMPLIFICAOR IFERENCIAL
Figura 1. Modelo del transistor BJT.
A)*ifica&+r &ifere(cia e! '( arre4+ reai9a&+ )e&ia("e "ra(!i!"+re!; e! e circ'i"+ *ri(ci*a &e +! a)*ifica&+re! +*eraci+(ae! i("e4ra&+! +"r+! ci rc'i"+! i(c+)erciae! "e4ra&+!; !e0 &e er%)'c8+! e ca!+ &e a)*ifica&+r &ifere(cia c+(!"r'i&+ a *ar"ir &e "ra(!i!"+re! $i*+are! + BJT, A4'(a! &e a! carac"er#!"ica! i)*+r"a("e! &e a)*ifica&+r &ifere(cia !+( !' a"a i)*e&a(cia &e e("ra&a; '(a 4a(a(cia &e "e(!i.( a"a; '( a+r a"+ e( c'a("+ a rec8a9+ e( )+&+ c+)6(,
Figura !. A"#li$i%ador i$eren%ial
AMPLIFICAOR OPERACIONAL
Figura (. Fuente de %orriente #or di*isor de *olta+e.
Figura &. iagra"a de un OPAMP LM'(1.
Se "ra"a &e '( &i!*+!i"i+ eec"r.(ic+ <'e "ie(e &+! e("ra&a! 0 '(a !ai&a, La !ai&a e! a &ifere(cia &e a! &+! e("ra&a! )'"i*ica&a *+r '( fac"+r /?- /4a(a(cia-=
Para e!"e circ'i"+ !e &a( a! ec'aci+(e!=
c+)6()e("e V+'" @ ?/V a*ica&+ V- e )%! e! ec+(+ci&+ UA71 +0 LM71,
-2
E OPAMP i&ea "ie(e '(a 4a(a(cia i(fi(i"a; '(a i)*e&a(cia &e e("ra&a i(fi(i"a; '( a(c8+ &e $a(&a "a)$i:( i(fi(i"+; '(a i)*e&a(cia &e !ai&a ('a; '( "ie)*+ &e re!*'e!"a ('+ 0 (i(46( r'i&+, C+)+ a i)*e&a(cia &e e("ra&a e! i(fi(i"a "a)$i:( !e &ice <'e a! c+rrie("e! &e e("ra&a !+( cer+, ………………………………………………
ESARROLLO TE)RICO Pri)er+ a("e! <'e (a&a (+! &e&ica)+! a reai9ar +! c%c'+! *ara c+(!"r'ir ('e!"ra f'e("e &e c+rrie("e &e 3)A 0 *ara e+ (+! $a!a)+! e( a *ri)era &e a! &+! +*ci+(e! <'e (+! &i+ e *r+fe!+r; <'e f'e *+r &ii!+r &e +"a2e; e c'a e! c+)+ e <'e !e )'e!"ra a c+("i('aci.( e( a fi4'ra =
-2
V, - R1/R10R! Ve - V, 3 4.'* Ie - / Ve 3 / 5Vee Re -- Ic
Pr+*+(e)+! R1 0 R3 @ , 0 &e e!"+; +$"e(e)+! <'e=
V, - /6.78 1&.68 /519* - 5'.9* -2 Ve - 5'.9* 3 4.'* - 57.!* S# <'ere)+! '(a c+rrie("e Ic @ 3)A=
Ie - /57.!* 0 19* Re - !"A De!*e2a)+! *ara fi(a)e("e +$"e(er e a+r &e Re=
Re - /57.!* 0 19* !"A Re - &.(8:
A8+ra <'e 0a +$"'i)+! ('e!"ra f'e("e &e c+rrie("e 0 a c+)*e)e("a)+! a ('e!"r+ circ'i"+; *r+ce&i)+! a reai9ar ('e!"r+ a(%i!i! "e.ric+ c+)*e"+ &e e!"e circ'i"+ 0 *ara e+ *ar"i)+! &e a i(!"r'cci.( &e *r+fe!+r <'e era a"erri9ar a! $a!e! &e +! "ra(!i!"+re! c+)+ !e )'e!"ra e( e !i4'ie("e &ia4ra)a; *ara 8aar a! c+rrie("e! 0 +"a2e!=
/AIc I$ Ie V+"! /VVc V$ Ve Vce V$c V$e
1' ,71' '
1' ,71' 7'
T1
T3
,G G HG,3 ,71 H,G G,3
,3 G HG,3 ,7 H,3 G,3
F'e("e &e c+rrie("e= A)*ere! /AIc I$ Ie Figura 9. iagra"a en #unto de o#era%i;n Par i$eren%ial.
<1-
3) 1,11) 3,G1) V+"!
/VVc H1,G1 V$ H7, Ve H,1 ESARROLLO E=PERIMENTAL
Ve< @ HV$e +(a ac"ia @K I+ @ 3VccRc Ic1 @ Ic3 @ I+ 2 α KK1
N
@ I+3
Vc< @ Vcc /I+3- Rc Vce1 @Vce3 @Vcc V$e /I+3- Rc Da&a! a! ec'aci+(e!; &e e!"a! )i!)a! *ar"i)+! *ara +$"e(er ('e!"r+! a+re! &e a! c+rrie("e! 0 +"a2e! re<'eri&+! e( e circ'i"+ <'e a c+("i('aci.( &e )'e!"ra(= A)*ere!
T1
T3
MATERIAL
3 Re!i!"e(cia! &e 5GQ 1 Re!i!"e(cia &e ,Q 3 Re!i!"e(cia! &e 1GQ 1 Re!i!"e(cia! &e 3,Q /!erieH *arae+3 Tra(!i!"+re! 3N3333A
C+( a a0'&a &e a(%i!i! *r+ce&i)+! a )e&ir a! c+rrie("e! 0 +"a2e! "a("+ *ara a f'e("e &e c+rrie("e c+)+ *ara + &e)%!; &+(&e (+! *'&i)+! &ar c'e("a <'e a *ri(ci*i+ 8a$#a *r+$e)a! 0a <'e ('e!"r+ circ'i"+ (+! &a$a e>ac"a)e("e '(a!
c+rrie("e! 0 +"a2e! !i)iare!; c+!a <'e &e!*':! (+! *'&i)+! &ar c'e("a <'e e!+ era !ea &e '( err+r e( e circ'i"+, Ca$e )e(ci+(ar a("e! <'e (a&a <'e a a 8+ra &e reai9ar e!"a! )e&ici+(e!; f'e (ece!ari+ )+&ificar a re!i!"e(cia e)i!+r &e a f'e("e &e c+rrie("e; 0a <'e e!"a (+ &a$a +! 3)A e>ac"+!; &a$a '(a c+rrie("e &e 1;7)A; a!i e! <'e &eci&i)+! a2'!"ar e!a r e!i!"e(cia <'e
Figura 6. Cone>i;n #ara %al%ular Ad.
Pr+ce&i)+! a )e&ir c+( e +!ci+!c+*i+ e +"a2e V+ c+( '(a *'("a 0 e V+H c+( +"ra
aca$.e9 !ie(&+ &e 3,, U(a "e(ie(&+ e!+; *r+ce&i)+! a 8acer a! )e&ici+(e!; +$"e(ie(&+ +! !i4'ie("e! a+re!= A)*ere! /AIc I$ Ie
T1
T3
51' 1G7' 1)
G5' 1G7' 1)
V+"! /VVc
T1
T3
,
,G
V V$e V ce V$c V$e
HGG,3 ,7 H,1 G,3
HGG,3 , H, G,5
A)*ere! /AIc I$ Ie
*ara *+&er i!'ai9ar a)$a! c'ra! 0 a!# )i!)+ *+&er re!"ara!=
-2
Vin - Vd - !44"V Vo - !.76*
a8+ra c+)+ 6"i)a )+&ificaci.( e( e circ'i"+; *ara a "ercera *ar"e f'e (ece!ari+ c++car a)$a! $a!e! e( '( !++ (+&+; c+)+ !e )'e!"ra a c+("i('aci.(=
3,1) 1) 3) V+"! /V-
Vc V$ Ve
H1,G3 H,15 H,7
Para + !i4'ie("e <'e f'e )e&ir a 4a(a(cia &ifere(cia; *ara e+ !e e a*ic. '(a !ea e( e!caa &e )V a '(a $a!e 0 a +"ra !e &e2. a"erri9a&a c+)+ !e )'e!"ra e( a !i4'ie("e i)a4e(=
Figura '. Cone>i;n #ara %al%ular A%n.
Te(ie(&+ a!# ('e!"r+ cir c'i"+; *r+ce&i)+! a 8acer a! )e&ici+(e! a'(<'e a8+ra i)*e)e("a(&+ '(a !ea 0a (+ e( e!caa &e )V !i(+ c+( '(a e!caa &e +"!; 0 a!# fi(a)e("e +$"e(er=
-2 RRNC @ P @ +4 / 1,5 1 3G)V @K RRNC = P = 41.52
C+(
-2
Vin - V%n - !.9* Vo - &44"V
A8+ra !++ c+( e!"+! a+re! *ara a *ar"e c'a"r+ (+! a0'&a)+! c+( a !i4'ie("e f.r)'a *ara cac'ar e a+r &e a reaci.( &e rec8a9+ e( (+&+ c+)6(=
RRNC - # -!4 log /Ad A%n
E( e!"a )i!)a !ecci.( &e re!'"a&+!; !i *'e&e( &i$'2a( a! !eae! &e +!ci+!c+*i+; ca&a c+( a <'e e!,
………………………………………………
RES?LTAOS Da&+! ('e!"r+! re!'"a&+! a("eri+re!= 3- ?a(a(cia &ifere(cia=
@K @K
A& @ V+ V& A& @ 3, 3GG)V A& @ 1,5 V
5- ?a(a(cia e( (+&+ c+)6(=
-2 -2
Ac( @ V+ Vc( Ac( @ 5GG)V 3, Ac( @ 13G)V
- Reaci.( &e rec8a9+ e( (+&+ c+)6(=
RRNC @ P @ +4 / A& Ac( -
DIA?RAMA DEL CIRCUITO
Figura 7. Cir%uito $inal@ Par i$eren%ial. ………………………………………………
CONCL?SIONES
………………………………………………
BIBLIORAFIA 1W B+0e!"a&; R, L,; Na!8e!0; L+'i!, Eec"r.(ica= Te+r#a &e Circ'i"+! 0 Di!*+!i"i+! Eec"r.(ic+!, PEARSON EDUCACIÓN; M:>ic+; 3GG, 3W T8+)a! I, F+0&= Di!*+!i"i+! Eec"r.(ic+!, 5W S, Se&ra; , C, S)i"8, Circ' i"+! Micr+ eec"r.(ic+!; Sa'(&er! C+e4e P'$i!8i(4; 13, W X+re(!"ei( Mar N, Micr+eec"r.(ica circ'i"+! 0 &i!*+!i"i+!, 3a, E&, Pre("ice Xa; 17
W Pa' B, $ar;A$er" Pa' Mai(+;Mic8ae A, Mie, Pr%c"ica! &e eec"r.(ica,
