3. TECHNICAL BRIEF
- 70 -
3.28. Mode Selection
Table 14 Mode Selection
MODE circuitry selects GMSK modulation (logic 0) or EDGE modulation (logic 1). VRAMP controls the
output power for GMSK modulation and provides bias optimization for EDGE modulation depending on
the state of MODE control.
3.29. PAM Schematic
MODE VMODE
RF
INPUT
VRAMP
TX
ENABLE
GSM
Low
Fixed
Vramp control output Power
High
EDGE
High
Ramp Burst Control
Vramp sets PA bias condition, fixed gain PA
High
Power Amp Module
NA
C449
0
R425
NA
NA
C455
C454
C453
NA
C460
68u
4
RSVD1
12
RSVD2
5
VBATT
6
VRAMP
GND20
32
GND21
31
30
GND22
GND23
29
28
GND24
27
GND25
13
GND3
11
GND4
10
GND5
GND6
17
GND7
18
19
GND8
GND9
20
7
GSM_IN
9
GSM_OUT
1
MODE
3
BS
2
DCS_PCS_IN
16
DCS_PCS_OUT
8
EN
15
GND1
GND10
21
GND11
22
GND12
23
GND13
24
GND14
25
26
GND15
GND16
36
GND17
35
GND18
34
GND19
33
14
GND2
U403
SKY77340
C461
27p
VSUPPLY
NA
C448
R427
0
1.2K
R441
C468
820p
NA
C470
R442
0
0
R443
NA
C469
TXON_PA
MODE
PALEVEL
C467
100p
R438
0
100
R437
100p
C464
100p
C465
NA
C466
VC2
VC1
Figure 41 PAM schematic
Summary of Contents for Prada KE850
Page 1: ...Date March 2007 Issue 1 0 Service Manual Model KE850 Service Manual KE850 ...
Page 3: ... 4 ...
Page 5: ... 6 ...
Page 71: ...4 PCB layout 72 Main PCB bottom Main PCB bottom placement ...
Page 115: ... 116 6 Download S W upgrade 6 Press the START button ...
Page 117: ...6 Download S W upgrade 118 KE850 KE850P40 7 V09a KE850 KE850P40 7 V09a ...
Page 127: ... 128 LGMC 8 pcb layout ...
Page 128: ... 129 LGMC 8 pcb layout ...
Page 129: ... 130 LGMC 8 pcb layout ...
Page 130: ... 131 LGMC 8 pcb layout ...
Page 131: ... 132 8 pcb layout ...
Page 132: ... 133 8 pcb layout ...
Page 133: ... 134 8 pcb layout ...
Page 134: ... 135 8 pcb layout ...
Page 135: ... 136 8 pcb layout ...
Page 136: ... 137 8 pcb layout ...
Page 137: ... 138 ...
Page 149: ... 150 ...
Page 151: ... 152 ...
Page 172: ...Note ...
Page 173: ...Note ...