Checking Vctcxo Block - LG KF700 Service Manual

4.14 Checking VCTCXO Block

The reference frequency (19.2MHz) from X100 (VCXO) is used UMTS TX part, GSM part and BB part.
TCXO
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
TP1
VREG_TCXO_2.85V
C140 C141
0.1u 0.01u
TP4
C143
TCXO_PM
1000p
C147
RTR6275_TCXO
1000p
TP3
[Fig. 4.10] Schematic of the TCXO Block
[Fig. 4.11] Test Point of the TCXO Block
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4. TROUBLE SHOOTING
X100
TP2
DSA321SCE-19.2M
R110
4 1
VCC VCONT
100ohm
3 2
OUTPUT GND C142
0.01u
8 5
NC4 NC1
7 6
NC3 NC2
R114
100K
C148
0.01u
U102
TC7SH04FS
TRK_LO_ADJ
VREG_BT_2.85V
C144
1000p
TCXO_BT
LGE Internal Use Only