LG B2000 Service Manual

3. TECHNICAL BRIEF
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3.3 13 MHz Clock (VCTCXO, X500)
The 13 MHz clock(X500) consists of a TCXO(Temperature Compensated Crystal Oscillator) which
oscillates at a frequency of 13 MHz. It is used within the Si4205, analog base band chipset (U101,
AD6537B), digital base band chipset (U100, AD6527).
3.4 Power Supplies for RF Circuits (RF LDO, U702)
Two regulators are used for RF circuits. One is MIC5255 (U702), and the other is one port of
AD6537B (U101).
MIC5255 (U702) supplies power to transceiver (SI4205, U500). One port of AD6537B supplies
power to VCTCXO (X500).
Figure 3-6 VCTCXO CIRCUIT DIAGRAM
APC
X500
2V75_VVCXO
13MHz
C536
22u
VCC
ONG
OUT VCONT
100
R514
1
2
3
4
C538
1000p
15K
R516
Table 3-2 RF POWER SUPPLIERS
Voltage
Powers
enabled signal
U702(VRF)
U101(VVCXO)
Battery(VBAT)
Supplier
2.85 V
2.75 V
3.4 ~ 4.2 V
U500
U501, U702
X500

LG B2000 Specifications

General

Brand	LG
Model	B2000
Category	Cell Phone
Language	English