Page 49 - 30105-2003 การวิเคราะห์วงจรอิเล็กทรอนิกส์ความถี่สูง

41
1. !!" # $
%&

k T

V = B %7 & ' ' ! +W $ '( k = 1.38 10 − 23 J K
×
T
B
q
$
T
+W $ & ' (K) '( q = 1.60 10 − 19 C
×
r b c ′
Q 1 r bb′ b′ C b c ′
r b e ′ g V r
C b e ′ V b e ′ m b e ′ ce
Q
2

r bb′ b′ C b c ′

r g V
m b e ′
C b e ′ b e ′ V b e ′

r b c ′ r ce

1.35 05'0ก1 '( ,,-* ' 3, $ - / %$ &! $ $!&!

0 10 mA

1.8 - ( g / %$ &! ! + 7 &
ก* + I C (dc ) =
m
ก. T = 25 C /. T = 40 C . T = − 10 C

A
A
A
I C ( ) I C ( )
c
d
d
c
9 + - ก ก (1.9) g m = =
V k T ) q
T ( B
×
×
" I C (dc ) = 10 mA,k = 1.38 10 − 38 J K,q = 1.60 10 − 19 C;
B
ก. T = 25 C T = (273 + 25) = 298 K

A
×
k T = 1.38 10 − 23 × 298 = 25.70 mV
B
×
q 1.60 10 − 19
×
10 10 − 3
g = = 389.105 mS
m
×
25.70 10 − 3

/ ( +W $" , 25 C g 389.105 mS

m
/. T = 40 C T = (273 + 40) = 313 K

A
×
k T = 1.38 10 − 23 × 313 = 26.996 mV
B
×
q 1.60 10 − 19
ก

ก
ก