13 Mhz Clock; Power Supplies And Control Signals - LG B2100 Service Manual

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, AD6537BABC),
digital base band chipset (U100, AD6527B). MIDI Chip (U203, ML287HB), Camera Chip (U601, CL761s)
3.4 Power Supplies for RF Circuits (RF LDO, U502)
Two regulators are used for RF circuits. One is MIC5255 (U502), and the other is one port of AD6537
(U101).
MIC5255 (U502) supplies power to transceiver (SI4205, U500). One port of AD6537 supplies power to
VCTCXO (X500). Main power (VBAT) from battery is used for PAM (RF3166, U501) because PAM requires
high power.
Supplier
U502(VRF)
U101(VVCXO)
Battery(VBAT)
Figure 3-6 VCTCXO CIRCUIT DIAGRAM
Voltage
2.85 V
2.75 V
3.4 ~ 4.2 V
Table 3-2 RF POWER SUPPLIERS
3. TECHNICAL BRIEF
Powers enabled signal
U500
X500
U501
CLKON
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