Power Supplies And Control Signals - LG MG220 Service Manual

3.3.3. Power Supplies and Control Signals

An external regulator(U502) is used to provide DC power to RF part. Every RF component except
power amp module uses this external regulator.
RF2.85V
C521
1u
VBAT
U502
R1114D281D-TR-F
3 1
VOUT VDD
2 4
GND1 NC
5 6
GND2 CE
Figure 6 External regulator Circuit
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3. H/W Circuit Description
RF_EN
C523 C524
1u 1000p