Page 40 - 30105-2003 การวิเคราะห์วงจรอิเล็กทรอนิกส์ความถี่สูง
P. 40
32
1. !!" # $
%&
− & ก ) / ( %$ &! !$ !0 8 (, +W $
0-25 C P 900 mW
D
− ก +W $" , ก 25 C P -( ' '
D
1.4 %$ &! P = 600 mW,T = 25 C,V EBO = 3 V, V CBO 20 V,
=
A
D
=
=
V 12 V, I 100 mA;! ก W ! P = 250 mW,V = 12 V;
CEO C (MAX) D CC
" &ก$ & + (ก* + V = 0.5V )
CE CC
9 + - ก ก (1.3) P = I V
D C CE
×
P 250 10 − 3
I = D = = 41.666 mA
C
×
0.5V CE 0.5 12
W ! P = == = 250 mW ! I C = 41.666 mA '( V CE = == = 6 V
D
1.4.1.6 .6!
' + (T
)
j
+W $ ! / ( * & . +W $ ! '&'tก&!
%$ &! - ก! 1.10 T = 150 C
j
1.4.1.7
.6!
(T stg )
$ 0 +W $ ( & . / ,&/! +W $ ( ! * 7
%$ &! * " ' W0
- ก! 1.10 T stg = − 65 7 150 C+ %$ &! *
!0 ! +W $ 65 C 7 150 C
−
1.4.2 ก4 ' )
/
'(& &ก ก0, ! / %$ &!
! 1.11 '0ก1 ( / %$ &!
'0ก1 ( +W $" , 25 C
$&! 05'0ก1 +
! ! !0 0 58.3
7
θ
(Thermal resistance Junction to Case) R C W
JC
! ! +W $" ,
7
(Thermal resistance Junction to Ambient) R 219 C W
θ
JA
+ &+! !0 &'/ ! & . ก!0 ก j$,
ก
ก
ก
