Checking Pam Block - LG L602i Service Manual

4. TROUBLE SHOOTING

4.6.4. Checking PAM Block

PAM Control Signal
TP1. GSM_PA_RAMP : Power Amp Gain Control. typically, 0.5V < Vapc < 2.6V,
TP2. GSM_PA_EN : Power Amp Enable
(Power ON : higher than 2.5V , Power OFF : lower than 0.7V)
TP3. GSM_PA_BAND : Power Amp Band Selection Control
(GSM Mode : lower than 0.7V , DCS/PCS Mode : higher than 2.5V)
TP4. +VPWR : PAM Supply Voltage Vcc higher than 3.28V
TP1
TP3
L1023
NA
C1041
10nH
TP2
Test Point (RF Tx Level)
L1021
C1030
C1026 NA
27p
3.9nH
R1015
15K
C1038
68p
NA
TP1
L1025
15
DCS_PCS_OUT
11
EGSM_OUT
19
RSVD_GND
SMPY0014001
21
P_GND
Schematic of PAM block
- 92 -
TP4
TP4
+VPWR
C1025
C1027 C1028
0.01u 0.01u
22u
C1039
C1040
0.01u
0.01u
TP2
3
DCS_PCS_IN
4
EGSM_IN
U1003
18
GSM_PA_EN
ENABLE
1
GSM_PA_BAND
BS
TP3