Samsung SGH-P400 Service Manual page 4

2 . S G H - P 4 0 0 C i r c u i t
1 . SGH - P 4 0 0 RF C i r c u i t D e s c r i p t i o n
1 ) RX P A RT
1 . A S M (U 1 0 0 5 )
ð 51 0 Sw i t c h i ngTx , R xp a t hf o rG SM9 0 0 , DCS1 8 0 0a ndP CS1 9 0 0b yl o g i c
c o nt r o l l i ng .
2. A SM Co nt r o lL o g i c ( U7 0 1 , U7 0 2, U7 0 3)
ð Tr u t h Ta b l e
GSMT xM o d e
DCS / P CS T xM o d e
P CS R xM o d e
GSM/ DCS R xM o d e
3. F I L TE R
To c o nv e r tE l e c t r o ma g ne t i c F i e l d W a v et o A c o u st i c W a v ea nd t h e n p a ss t h e
sp e c i f i c f r e q u e nc yb a nd .
-G SM F I L TE R ( C1 0 0 3, C1 0 0 4 , L 1 0 0 1 )
ð F o rf i l t e r i ngt h ef r e q u e nc yb a nd b e t w e e n 9 25 ~ 9 60MH z
-DCS F I L TE R ( C1 0 0 5, C1 0 0 6, L 1 0 0 2)
ð F o rf i l t e r i ngt h ef r e q u e nc yb a nd 1 8 0 5 a nd 1 8 8 0M H z .
-P CS SA W F I L TE R ( F 1 0 0 3, C1 0 0 9 , C1 0 1 0 , L 1 0 0 6)
ð F o rf i l t e r i ngt h ef r e q u e nc yb a nd b e t w e e n 1 9 30a nd 1 9 9 0M H z
4 . TC- VCXO ( OSC8 0 1 )
To g e ne r a t et h e1 3MH z r e f e r e nc ec l o c k t o d r i v et h el o g i c a nd R F .
A f t e ra d d i t i o na lp r o c e ss, t h er e f e r e nc ec l o c ki s a p p l i e d t o t h eU9 0 0RxI Q
d e mo d u l a t o ra nd TxI Q mo d u l a t o r .
Th e o sc i l l a t o r f o r R X I Q d e mo d u l a t o r a nd Tx mo d u l a t o r a r e c o nt r o l l e d b y
s e r i a l d a t a t o se l e c t c h a nne l a nd u se f a st l o c kmo d e f o r G P RS h i g h c l a ss
o p e r a t i o n.
D e s c r i p t i o n
VC1
H
L
L
L
SAMSUNG Proprietary-Contents may change without notice
This Document can not be used without Samsung's authorization
VC2
L
H
L
L
2- 1
VC3
L
L
H
L