LG -T300 Service Manual page 33

3. TECHNICAL BRIEF
The RF7161 also integrates an ESD filter to provide excellent ESD protection at the antenna port.
The RF7161 is designed to provide maximum efficiency at rated POUT.
1. X = DON'T CARE
2. RX1, RX2, RX3, and RX4 are broadband receive ports and each supports the GSM850, GSM900, DCS, and PCS bands.
RF PART
GND401 GND402
ANT401
C408 R403
C403
DNI 2.7n
1n
C404 7p
C401
C407
5.6n
1p
TX_EN
MODE
(TX_ENABLE)
LOW POWER MODE LOW
RX1(EGSM_RX)
LOW
RX2(GSM850_RX) LOW
RX3(PCS_RX) LOW
RX4(DCS_RX) LOW
GSM850/900_TX HIGH
DCS/PCS_TX HIGH
LGE Internal Use Only
Figure 3.3.2 Band SW Logic Table
TX_RAMP
TX_EN
BS1
BS2
BS3
SW401
C442
C405
1.2p
DNI
BS3 BS2 BS1
(GPCTRL2) (GPCTRL1) (GPCTRL0)
LOW LOW LOW
HIGH LOW LOW
LOW HIGH LOW
LOW HIGH HIGH
LOW LOW HIGH
LOW HIGH LOW
LOW HIGH HIGH
Figure 3.3.3 FEM CIRCUIT DIAGRAM
R401 1K
C421 C413 C424 C423 C426
1n 1n 1n 1n 39p
17
GPCTRL2
16
GND9
15 U401
GND8
14
ANT
13
DCS
RX4
12
PCS
RX3
GSM850
EGSM
FL402
C416 33p DCS
1 8
IN_1842_5 OUT_1842_5
C417 33p
PCS
4 9
IN_1960 OUT_1960
2 7
GND1 GND2
3 6
GND3 GND4
5 10
GND5 GND6
1805M1880M,1930M1990M
FL401
GSM850
C418 33p
1 8
IN_881_5 OUT_881_5
C427 33p EGSM
4 9
IN_942_5 OUT_942_5
2 7
GND1 GND2
3 6
GND3 GND4
5 10
GND5 GND6
869M894M,925M960MHz
- 4 -
Copyright © 2010 LG Electronics. Inc. All right reserved.
3. TECHNICAL BRIEF
VBAT
C412 C415
C425 C419
10n 33p
4.7u 4.7u
1
GND1
2
GND2
C409 56p
3
RFIN_LB
4
L404 3.3n L403 3.3n
GND3
C410 22p
5
RFIN_HB
6
GND4
DCS_PCS_OUT
L405
1.5n
C422
1p
RX34X
C411 1.8n
L402 L408
1.8n
68n
RX34
1.8n
C420
22p
L409
RX12X
L407
12n 33n
L410
RX12
L406
22p
Only for training and service purposes
GSM_OUT