Checking Pam Block - LG KS20 Operating Instructions Manual

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
C539
4.7p
C541
15p
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Only for training and service purposes
TP4
VBAT
C533
100p
TQM7M5008
C540
14
GND6
33p
13
GND5
L512
12
2.2nH
VCC
U501
11 TQM7M5008
GND4
10
GND3
L513
9
GSM_OUT
6.8nH
8
GND2
L514
12nH
- 99 -
4. TROUBLE SHOOTING
R510
2.2K
C538
C534
68p
22u
(1608)
1
DCS_PCS_IN
2
BS
3
TX_EN
4
VBATT
5
GND1
FL501
6
VRAMP
EFCH897MTDB1
SFSY0030201
7
GSM_IN
TP1
TP2
GSM_PA_RAMP
GSM_PA_BAND
GSM_PA_EN
TP3
4 5
O1 G3
1
IN
G2 G1
3 2
LGE Internal Use Only