c f ri

SZACOWANIE PARAMETRÓW WZMACNIACZA TRANZYSTOROWEGO
konfiguracja Wspólnego Emitera (OE)
+ EC
Dane
RC
RB1
ϕT ≈ 26mV
C2 WY
WE
U EY ≈ 50 ÷ 300V
C1
U CEQ , I CQ − pkt.pracy
β 
RG
RL
RB2
EG
CE
~
rwe
Parametry tranzystora
gm =
rbe =
rce =
cbe =
rweT = rbe
ϕT
β
rwy
rwyT = rce
Parametry robocze ( przy CE→∞ )
rwe = RB1 || RB 2 || rbe
1
424
3
I CQ
RE
≈
RB >> rbe
rbe
Częstotliwości graniczne
fd =
f d21 + f d22 + f dE2
RB
rwy = rce || RC
gm
U EY + U CEQ
I CQ
gm
− cbc
2 ⋅ π ⋅ fT
cwe = cbe + cbc (1 − ku )
≈
rce >> RC
RC
kusk = − g m ⋅ Robc ⋅ γ u
{ {
RL ||rwy
r
14243 rwe +weRG
ku

fT z katalogu
cbc 
rbb' dla m.cz. = 0
f d 1 (C1 ) =
1
2 ⋅ π ⋅ C1 ⋅ (RG + rwe )
f d 2 (C2 ) =
1
2 ⋅ π ⋅ C2 ⋅ (RL + rwy )
f dE (C E ) =
fg =
β
2 ⋅ π ⋅ C E ⋅ (RG || RB + rbe )
1
2 ⋅ π ⋅ cwe ⋅ rwe RG
SZACOWANIE PARAMETRÓW WZMACNIACZA TRANZYSTOROWEGO
konfiguracja Wspólnego Emitera (OE) ze sprzężeniem zwrotnym
+ EC
Dane
RC
RB1
ϕT ≈ 26mV
C2 WY
WE
U EY ≈ 50 ÷ 300V
C1
U CEQ , I CQ − pkt.pracy
β 
RG

fT z katalogu
cbc 
rbb' dla m.cz. = 0
RL
RB2
EG
RE
~
rwe
rweT = rbe + RE (β + 1)
Parametry tranzystora
gm =
rbe =
rce =
cbe =
I CQ
[rbe + RE (β + 1)]
RB
rwy = rce || RC
gm
U EY + U CEQ
I CQ
gm
− cbc
2 ⋅ π ⋅ fT
cwe = cbe
rwyT = rce
Parametry robocze ( przy CE = 0)
rwe = RB1 RB 2
1
424
3
ϕT
β
rwy
rbe
+ cbc (1 − ku )
rbe + (β + 1)RE
≈
rce >> RC
RC
rbe
kusk = − g m ⋅ Robc ⋅
⋅ γ
{ r + R (β + 1) {u
be
E
R ||r
r
144L4wy4244443 rwe +weRG
g R
R
ku ≈ − m C ≈ − C
RE
1+ g m RE
Częstotliwości graniczne
fd =
f d21 + f d22
f d 1 (C1 ) =
1
2 ⋅ π ⋅ C1 ⋅ (RG + rwe )
f d 2 (C2 ) =
1
2 ⋅ π ⋅ C2 ⋅ (RL + rwy )
fg =
1
2 ⋅ π ⋅ cwe ⋅ rwe RG
SZACOWANIE PUNKTU PRACY
WZMACNIACZA TRANZYSTOROWEGO
+ EC
RB1
RC
RC
ICQ
ICQ
IBQ
IBQ
tw. Thevenina
UCEQ
RB2
+ EC
R B = R B1 R B 2
RB 2
U B = EC
R B1 + R B 2
UBEQ
UCEQ
RB
II
UBEQ
RE
RE
I
+ UB
Dane
U BEQ ≈ 0,65V
β
Punkt pracy
z I ⇒ U B = I BQ RB + I EQ RE + U BEQ 
U B − U BEQ
 
z II ⇒ EC = I EQ RE + U CEQ + I CQ RC   I CQ = βI BQ = β
RB + (β + 1)RE
 
⇒
 

β +1 
 U
+
R
RC  ≈
I CQ = βI BQ
CEQ = EC − I CQ 
E
{ EC − I CQ (RE + RC )

 
β

 I EQ ≈ I CQ
 
I EQ = I CQ + I BQ
