Nokia 3105 Servicehandbuch

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RH-48
Troubleshooting - RF
CCS Technical Documentation
Page 14
 ©
2003 Nokia Corporation         Confidential
Issue 1 11/2003
Cell Power Amplifier
The power amplifier (PA) has the DC/DC converter (PMIC device), which controls the 
transmitter. The following tables show the circuits that have an effect on the transmitter 
path and how to troubleshoot them.
*Not an actual FlaLi tuning PDM. PDM to produce approximately 25dBm at antenna connector.
Tx AGC (6)
-94
15
6
24
Tx AGC (7)*
-280*
25
21
27
PA Power and Gain Measurements
Power Amplifier Input 
Test Point
Power Amplifier Output 
Test Point
pin3-Z601
left-R814
PA Power and Gain Specifications
Mode
Name
Power 
Output 
Range
Nominal 
Gain
Vcc Range
Vcc Test 
Point
Gain mode 0
V0
up to 6
23.8
0.75- 0.88
C806
Gain mode 1
V1
6 to 11
25.2
1.125- 1.375
C806
Gain mode 3
V2
Not used
Not used
2 - 2.5
C806
Gain mode 2
Bypass
11 up
29
3 - 4
C806
Overall Gain
V0 to 
Bypass
6
3.5  to  7.3 
+/- 0.5
unit
N/A
dBm
dB
VDC
N/A
Phoenix Control and Example Values
PA Gain Step
Gen IO 12     GenIO13
PA Vcc
volt (v)
Spec 
Name
L
L
0.8
V0
H
L
1.2
V1
L
H
2.2
V2
H
H
3.7
Bypass
Tx AGC Tuning
Tx Tuning 
AGC Step
Tx AGC 
PDM 
Value
Target 
Power
Low Limit
High Limit