LG KS20 - Checking VCTCXO Block

LGE Internal Use Only Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
4. TROUBLE SHOOTING
- 87 -
4.4 Checking VCTCXO Block
The reference frequency (19.2MHz) from X100 (TCXO) is used in UMTS TX
part, GSM part and BB part.
TCXO Circuit
0.1uF
C544
100p C548
VTCXO_2.85V
TG-5010LH_19_2M_75A
EXSK0007802
2
GND
3
OUT
VCC
4
VCONT
1
X500
19.2MHz
1000p C552
C542
1000p
R517
100ohm
0.01u
C551
TCXO_RTR_19.2MHz
TCXO_PM_19.2MHz
RTR_TRK_LO_ADJ
TP1
TP3
TP4 TP2
Schematic of the TCXO Block
Test Point of the TCXO Block
TP1
TP4
TP3
TP2