LG KS20 - Checking Pam Block

LGE Internal Use Only Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
4. TROUBLE SHOOTING
- 99 -
4.7.4 Checking PAM Block
TP1. GSM_PA_RAMP : Power Amp Gain Control. typically, 0.2V < Vramp < 1.6V
TP2. GSM_PA_EN : Power Amp Enable
(Power ON : higher than 1.25V , Power OFF : lower than 0.4V)
TP3. GSM_PA_BAND : Power Amp Band Selection Control
(GSM Mode : -0.2V < VBS < 0.4V , DCS/PCS Mode : 1.25V < VBS < 3.0V)
TP4. +VPWR : PAM Supply Voltage Vcc higher than 3.0V
Schematic of GSM PAM Block
(1608)
SFSY0030201
TQM7M5008
14
GND6
16
GND7 GND8
17
GSM_IN
7
GSM_OUT
9
3
TX_EN
VBATT
4
VCC
12
6
VRAMP
TQM7M5008
U501
BS
2
DCS_PCS_IN
1
15
DCS_PCS_OUT
GND1
5
8
GND2
GND3
10
11
GND4
13
GND5
33p
C540
2.2K
R510
4.7p
C539
L514
12nH
6.8nH
L513
C534
22u
VBAT
100p
C533
15p
C541
FL501
EFCH897MTDB1
G1
2
G2
3
G3
5
IN
1
O1
4
L512
2.2nH
68p
C538
GSM_PA_BAND
GSM_PA_EN
GSM_PA_RAMP
TP2
TP4
TP3
TP1