Page 148 - 30105-2003 การวิเคราะห์วงจรอิเล็กทรอนิกส์ความถี่สูง

140

3.

R
R
V CC TH V CC TH ;
ก !ก (2.28) R = , R =
B 1 B 2 )
V TH ( CC − V TH
V

"#
3.15 ก ก
9 R , R % R
E B 1 B 2
- ,
ก !ก (3.23) V CE = 0.5V CC ,V RE = 0.5V CC ;

=
×
V CE = 0.5 12 6 V

×
=
V RE = 0.5 12 6 V
×
I 10 10 − 3
I = C = = 83.333 µA
B
β 120
F
×
0.5V 0.5 12
ก !ก (3.24) R = CC = = 595.043 Ω
E
(β + ) 1 I B (120 1 83.333 10+ ) × − 6
F
=
×
ก !ก (2.26) R TH = 15R = 15 595.043 8.925 kΩ
E
ก !ก (2.27) V TH = I R + V BE + (β + ) 1 I R
B E
F
B TH
×
×
V TH = ( 83.333 10 − 6 × 8.925 10 3 ) + 0.6
+ ( 121 83.333 10 − 6 × 595.043 )
×
×
V TH = 7.343 V
×
×
V CC TH 12 8.925 10 3 14.585 kΩ
R
ก !ก (2.28) R B 1 = = =
V TH 7.343
×
×
V CC TH 12 8.925 10 3
R
R B 2 = = = 22.997 kΩ
V
( CC − V TH ) (12 7.343− )
" R = == = 595.043 , R B 1 = = = = 14.585 k , R B 2 = = = = 22.997 k ;
Ω
Ω
Ω
Ω Ω Ω
Ω Ω Ω
Ω Ω Ω
E
3.6.3 ก
$

"*

@.* $I

"
J
R = 595.043 Ω +;
9 ! & D
R = 560 Ω
E
E
R = 14.585 kΩ +;
9 ! & D
R = 15 kΩ
B 1 B 1
R = 22.997 kΩ +;
9 ! & D
R = 22 kΩ
B 2 B 2
3.6.4 ก
"
+ & ,

+ "
! "- 9 !&

! & D

V − V )
ก !ก (2.3) I = ( TH BE
B
R + ( β + ) 1 R
TH F E
I
ก !ก (2.4) I = β F B
C
ก !ก (3.23) V = 0.5V ,V = 0.5V ;
CE CC RE CC
ก

ก
ก