LG GD910 Service Manual page 94

GSM PAM Circuit Diagram
TP1
. .
L426
NA
TP2
C509
6.8p
. .
L405
27nH
TP3
L406
2.7nH
. .
C449
C450
1.5p
10n
Test Point Net name
TP4 PA_LEVEL
TP5 VBAT
Table 1.
Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
SW400
C
MM8130-2600
1
G3 G4
OUT IN
G2 G1
C517
DNI
PGND
15
GND3
8
GND2
11
GND1
14
U402
BY_CAP2
9
BY_CAP1
13
GSM850_900_OUT
10
DCS_PCS_OUT
12
TQM7M5005
C451
10n
Description
Power Amp Gain Control. Typically, 0.2 ~1.6V
PAM Supply Voltage (Vcc > 3V)
GD910 service manual
. .
VBAT
GSM850_900_IN
7
TX_EN
6
. .
VRAMP
5
VBATT
4
BS
3
MODE_SELECT
2
DCS_PCS_IN
1
C453 C448 C454 C455
33p 10u 18p 0.1u
- 95 -
5. Trouble shooting
TP4
LBAND_IN
TXON_PA
R408 1.2K
PA_LEVEL
. .
2G_BS
PA_MODE
HBAND_IN
TP5
C456
39p
LGE Internal Use Only