Checking Tcxo Block - LG -P500 Service Manual

4. TROUBLE SHOOTING

4.3 Checking TCXO Block

The output frequency (19.2MHz) of TCXO (X200) is used as the reference one of RTR6285 and PM7540 internal
VCO.
TCXO Circuit
R205 100
RTR_TRK_LO_ADJ
Clesed to TCXO
TP2
LGE Internal Use Only
TP3
TP2
X200
1 3
VCONT OUT
2 4
C208
GND VCC
10n
19.2MHz
KT3225L19200DCW28RA0
1.0T
Schematic of the Crystal Part (19.2MHz)
TP1
TP1
VREG_TCXO_2.85V
C206
C205
0.1u
1n
C207 330p
TCXO_PM_19.2MHZ
C210
330p
TCXO_RTR_19.2MHZ
TP3
FFA Rev.C(220Ohm@100MHz)
R208 220
VREG_MSMA_2.6V
1
TCXO_EN
C221 330p 2
- 80 -
Copyright © 2010 LG Electronics. Inc. All right reserved.
TP2
TP1
C220 0.1u
5
VCC
4
TP3
R209 33
U201
USBH_SYSCLK
GND
3
R210 100K
Only for training and service purposes