LG L602i Service Manual
Date: June, 2007 / Issue 1.0
Service Manual
Model : L602i
Service Manual
L602i
L602i SVC (9)_Cover_0628 1904.1.9 1:42 PM ˘`1
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1. INTRODUCTION .............................. 5
1.1 Purpose................................................... 5
1.2 Regulatory Information............................ 5
2. PERFORMANCE...............................7
2.1 System Overview .....................................7
2.2 Usable environment .................................8
2.3 Radio Performance ..................................8
2.4 Current Consumption.............................14
2.5 Antenna BAR .........................................14
2.6 Battery BAR ...........................................15
2.7 Sound Pressure Level............................16
2.8 Charging ................................................16
3. TECHNICAL BRIEF ........................17
3.1 General Description ...............................17
3.2 GSM Mode.............................................19
3.3 WCDMA Mode .......................................23
3.4 LO Phase-locked Loop ..........................26
3.5 Off-chip RF Components .......................28
3.6 Digital BaseBand(DBB/MSM6250A)......34
3.7 Hardware Architecture ...........................36
3.8 Subsystem(MSM6250A) ........................37
3.9 External memory interface .....................40
3.10 H/W Sub System..................................41
3.11 Main Features ......................................65
4. TROUBLE SHOOTING ...................70
4.1. RF Component......................................70
4.2. SIGNAL PATH ......................................72
4.3. Checking VCXO Block ..........................74
4.4. Checking Ant. SW Module Block ..........77
4.5. Checking WCDMA Block ......................79
4.6. Checking GSM Block ............................87
4.7 Power ON Trouble .................................94
4.8 USB Trouble ..........................................96
4.9 SIM Detect Trouble ................................97
4.10 Key Sense Trouble ..............................98
4.11 VGA Camera Trouble ..........................99
4.12 1.3M Camera Trouble ........................100
4.13 Main LCD Trouble..............................101
4.14 Folder ON/OFF Trouble .....................103
4.15 Camera Direction Change Trouble ....104
4.16 Audio Trouble Shooting .....................105
4.17 Charger Trouble Shooting..................117
5. DOWNLOAD..................................119
5.1 Introduction ..........................................119
5.2 Downloading Procedure.......................119
5.3 Troubleshooting Download Errors .......128
5.4 Caution.................................................133
6. BLOCK DIAGRAM ........................134
6.1 GSM & WCDMA RF Block...................134
6.2 Interface Diagram ................................136
7. Circuit Diagram ............................141
8. pcb layout .....................................150
9. Calibration Program ....................157
9.1 Configuration of HOT KIMCHI .............157
9.2 How to use HOT KIMCHI.....................160
10. EXPLODED VIEW &
REPLACEMENT PART LIST ..... 163
10.1 EXPLODED VIEW ............................ 163
10.2 Replacement Parts
<Mechanic component>.................... 165
<Main component> ........................... 170
10.3 Accessory ......................................... 191
Table Of Contents
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1.1 Purpose
This manual provides the information necessary to repair, calibration, description and download the
features of this model.
1.2 Regulatory Information
A. Security
Toll fraud, the unauthorized use of telecommunications system by an unauthorized part (for example,
persons other than your company’s employees, agents, subcontractors, or person working on your
company’s behalf) can result in substantial additional charges for your telecommunications services.
System users are responsible for the security of own system. There are may be risks of toll fraud
associated with your telecommunications system. System users are responsible for programming and
configuring the equipment to prevent unauthorized use. The manufacturer does not warrant that this
product is immune from the above case but will prevent unauthorized use of commoncarrier
telecommunication service of facilities accessed through or connected to it. The manufacturer will not
be responsible for any charges that resultfrom such unauthorized use.
B. Incidence of Harm
If a telephone company determines that the equipment provided to customer is faulty and possibly
causing harm or interruption in service to the telephone network, it should disconnect telephone
service until repair can be done. A telephone company may temporarily disconnect service as long as
repair is not done.
C. Changes in Service
A local telephone company may make changes in its communications facilities or procedure. If these
changes could reasonably be expected to affect the use of the phones or compatibility with the net
work, the telephone company is required to give advanced written notice to the user, allowing the user
to take appropriate steps to maintain telephone service.
D. Maintenance Limitations
Maintenance limitations on the phones must be performed only by the manufacturer or its authorized
agent. The user may not make any changes and/or repairs expect as specifically noted in this manual.
Therefore, note that unauthorized alternations or repair may affect the regulatory status of the system
and may void any remaining warranty.
1. INTRODUCTION
1. INTRODUCTION
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E. Notice of Radiated Emissions
This model complies with rules regarding radiation and radio frequency emission as defined by local
regulatory agencies. In accordance with these agencies, you may be required to provide information
such as the following to the end user.
F. Pictures
The pictures in this manual are for illustrative purposes only; your actual hardware may look slightly
different.
G. Interference and Attenuation
A phone may interfere with sensitive laboratory equipment, medical equipment, etc. Interference from
unsuppressed engines or electric motors may cause problems.
H. Electrostatic Sensitive Devices
ATTENTION
Boards, which contain Electrostatic Sensitive Device (ESD), are indicated by the sign.
Following information is ESD handling:
• Service personnel should ground themselves by using a wrist strap when exchange system boards.
• When repairs are made to a system board, they should spread the floor with anti-static mat which is
also grounded.
• Use a suitable, grounded soldering iron.
• Keep sensitive parts in these protective packages until these are used.
• When returning system boards or parts like EEPROM to the factory, use the protective package as
described.
1. INTRODUCTION
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2. PERFORMANCE
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2.1 System Overview
2. PERFORMANCE
Item Specification
Shape Clamshell Slide
Size 96 x 49 x 17mm
Weight 100 g (with 860 mAh Battery)
Power 3.7V normal, 860 mAh Li-Polymer
Talk Time Over 140 Min (WCDMA, Tx=10dBm, Voice Call)
(with 860mAh) Over 90 Min (WCDMA, Tx=10dBm, Video Call)
Over 200 Min (GSM, Tx=29dBm, Voice)
Standby Time WCDMA Stand by:
(with 860mAh) Static Stand-by : Over 380 hrs (Auto mode)
Dynamic Stand-by : Over 250 hrs (Auto mode)
GSM Stand by:
Static Stand-by : Over 260 hrs (Auto mode)
Antenna Internal Antenna
LCD Main 176 X 220 pixel (TFT)
LCD Backlight White
Camera 1.3 Mega pixel (CMOS) + VGA Camera
Vibrator Yes (Coin cell type)
LED Indicator Yes (2 color LED )
MIC Yes
Speaker Yes
Receiver Yes
Earphone Jack Yes
Connectivity USB 1.1, IrDA
Volume Key Push Type(+, -)
External Memory No
I/O Connect 10 Pin (ARIB Connector Type A)
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2.2 Usable environment
1) Environment
2) Environment (Accessory)
* CLA : 12 ~ 24 V(DC)
2.3 Radio Performance
1) Transmitter - GSM Mode
* In case of DCS : [A] -> 1710, [B] -> 1785 * In case of PCS : [A] -> 1850, [B] -> 1910
2. PERFORMANCE
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Item Specification
Voltage 3.7 V(Typ), 3.38 V(Min), [Shut Down : 3.28 V]
Operation Temp -20 ~ +60°C
Storage Temp -20 ~ +70°C
Humidity 85 % (Max)
Reference Spec. Min Typ. Max Unit
TA Power Available power 100 220 240 Vac
No Item GSM DCS & PCS
100k~1GHz -39dBm
9k ~ 1GHz -39dBm
MS allocated 1G~[A]MHz -33dBm
Channel
1G~12.75GHz -33dBm
[A]M~[B]MHz -39dBm
Conducted [B]M~12.75GHz -33dBm
1Spurious 100k~880MHz -60dBm 100k~880MHz -60dBm
Emission 880M~915MHz -62dBm 880M~915MHz -62dBm
Idle Mode
915M~1GHz -60dBm 915M~1GHz -60dBm
1G~[A]MHz -50dBm 1G~[A]MHz -50dBm
[A]M~[B]MHz -56dBm [A]M~[B]MHz -56dBm
[B]M~12.5GHz -50dBm [B]M~12.5GHz -50dBm
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2. PERFORMANCE
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* In case of DCS : [A] -> 1710, [B] -> 1785 * In case of PCS : [A] -> 1850, [B] -> 1910
No Item GSM DCS & PCS
30M ~ 1GHz -36dBm
30M~1GHz -36dBm
MS allocated 1G~[A]MHz -30dBm
Channel
1G ~ 4GHz -30dBm
[A]M~[B]MHz -36dBm
Radiated [B]M~4GHz -30dBm
2Spurious 30M ~ 880MHz -57dBm 30M~880MHz -57dBm
Emission 880M ~ 915MHz -59dBm 880M~915MHz -59dBm
Idle Mode
915M~1GHz -57dBm 915M~1GHz -57dBm
1G~[A]MHz -47dBm 1G~[A]MHz -47dBm
[A]M~[B]MHz -53dBm [A]M~[B]MHz -53dBm
[B]M~4GHz -47dBm [B]M~4GHz -47dBm
3 Frequency Error ±0.1ppm ±0.1ppm
4 Phase Error
±5(RMS) ±5(RMS)
±20(PEAK) ±20(PEAK)
3dB below reference sensitivity 3dB below reference sensitivity
Frequency Error RA250 : ±200Hz RA250: ±250Hz
5 Under Multipath and HT100 : ±100Hz HT100: ±250Hz
Interference Condition TU50 : ±100Hz TU50: ±150Hz
TU3 : ±150Hz TU1.5: ±200Hz
0 ~ 100kHz +0.5dB 0 ~ 100kHz +0.5dB
200kHz -30dB 200kHz -30dB
250kHz -33dB 250kHz -33dB
Due to 400kHz -60dB 400kHz -60dB
Output RF
modulation 600 ~ 1800kHz -66dB 600 ~ 1800kHz -60dB
6 1800 ~ 3000kHz -69dB 1800 ~ 6000kHz -65dB
Spectrum
3000 ~ 6000kHz -71dB ≥6000kHz -73dB
≥6000kHz -77dB
Due to
400kHz -19dB 400kHz -22dB
Switching
600kHz -21dB 600kHz -24dB
transient
1200kHz -21dB 1200kHz -24dB
1800kHz -24dB 1800kHz -27dB
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2. PERFORMANCE
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No Item GSM DCS & PCS
Frequency offset 800kHz
7 Intermodulation attenuation –
Intermodulation product should
be Less than 55dB below the
level of Wanted signal
Power control
Power Tolerance
Power control
Power Tolerance
Level (dBm) (dB) Level (dBm) (dB)
533±3 030±3
631±3 128±3
729±3 226±3
827±3 324±3
925±3 422±3
10 23 ±3 5 20 ±3
8Transmitter Output Power 11 21 ±3 6 18 ±3
12 19 ±3 7 16 ±3
13 17 ±3 8 14 ±3
14 15 ±3 9 12 ±4
15 13 ±3 10 10 ±4
16 11 ±5 11 8 ±4
17 9 ±5 12 6 ±4
18 7 ±5 13 4 ±4
19 5 ±5 14 2 ±5
15 0 ±5
9 Burst timing Mask IN Mask IN
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2. PERFORMANCE
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2) Transmitter - WCDMA Mode
No Item Specification
1 Maximum Output Power Class 3 : +24dBm(+1/-3dB)
2Frequency Error ±0.1ppm
3 Open Loop Power control in uplink ±9dB@normal, ±12dB@extreme
Adjust output(TPC command)
cmd 1dB 2dB 3dB
+1 +0.5/1.5 +1/3 +1.5/4.5
4 Inner Loop Power control in uplink 0 -0.5/+0.5 -0.5/+0.5 -0.5/+0.5
-1 -0.5/-1.5 -1/-3 -1.5/-4.5
Group (10 equel command group)
+1 +8/+12 +16/+24
5 Minimum Output Power -50dBm(3.84MHz)
Qin/Qout : PCCH quality levels
6Out-of-synchronization handling of output power Toff@DPCCH/Ior : -22 -> -28dB
Ton@DPCCH/Ior : -24 -> -18dB
7 Transmit OFF Power -56dBm(3.84MHz)
8 Transmit ON/OFF Time Mask
±25us
PRACH,CPCH,uplinlk compressed mode
±25us
9 Change of TFC
Power varies according to the data rate
DTX : DPCH off
(minimize interference between UE)
10 Power setting in uplink compressed ±3dB(after 14slots transmission gap)
11 Occupied Bandwidth(OBW) 5MHz(99%)
-35-15*(∆f-2.5)dBc@∆f=2.5~3.5MHz,30k
12 Spectrum emission Mask
-35-1*(∆f-3.5)dBc@∆f=3.5~7.5MHz,1M
-39-10*(∆f-7.5)dBc@∆f=7.5~8.5MHz,1M
-49dBc@∆f=8.5~12.5MHz,1M
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3)Receiver - GSM Mode
2. PERFORMANCE
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No Item Specification
13 Adjacent Channel Leakage Ratio(ACLR)
33dB@5MHz, ACP>-50dBm
43dB@10MHz, ACP>-50dBm
-36dBm@f=9~150KHz, 1K BW
-36dBm@f=50KHz~30MHz, 10K BW
-36dBm@f=30MHz~1000MHz, 100K BW
14
Spurious Emissions -30dBm@f=1~12.5GHz, 1M BW
(*: additional requirement) (*)-41dBm@f=1893.5~1919.6MHz, 300K
(*)-67dBm@f=925~935MHz, 100K BW
(*)-79dBm@f=935~960MHz, 100K BW
(*)-71dBm@f=1805~1880MHz, 100K BW
15 Transmit Intermodulation
-31dBc@5MHz,Interferer -40dBc
-41dBc@10MHz, Interferer -40dBc
16 Error Vector Magnitude (EVM)
17.5%(>-20dBm)
(@12.2K, 1DPDCH+1DPCCH)
17 Transmit OFF Power
-15dB@SF=4.768Kbps, Multi-code
transmission
No Item GSM DCS & PCS
1
Sensitivity (TCH/FS Class II) -102dBm -102dBm
2
Co-Channel Rejection
C/Ic=7dB Storage -30 ~ +85
(TCH/FS Class II, RBER, TU high/FH)
3 Adjacent Channel 200kHz C/Ia1=-12dB C/Ia1=-12dB
Rejection 400kHz C/Ia2=-44dB C/Ia2=-44dB
Wanted Signal :-98dBm Wanted Signal :-96dBm
4
Intermodulation Rejection 1st interferer:-44dBm 1st interferer:-44dBm
2nd interferer:-45dBm 2nd interferer:-44dBm
5
Blocking Response Wanted Signal :-101dBm Wanted Signal :-101dBm
(TCH/FS Class II, RBER)
Unwanted : Depend on Frequency Unwanted : Depend on Frequency
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2. PERFORMANCE
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4) Receiver - WCDMA Mode
No Item Specification
1 Reference Sensitivity Level -106.7 dBm(3.84 MHz)
-25dBm(3.84MHz)
2Maximum Input Level -44dBm/3.84MHz(DPCH_Ec)
UE@+20dBm output power(Class3)
3 Adjacent Channel Selectivity (ACS)
33dB
UE@+20dBm output power(Class3)
-56dBm/3.84MHz@10MHz
4In-band Blocking UE@+20dBm output power(Class3)
-44dBm/3.84MHz@15MHz
UE@+20dBm output power(Class3)
-44dBm/3.84MHz@f=2050~2095 and
2185~2230MHz
UE@+20dBm output power(Class3)
-30dBm/3.84MHz@f=2025~2050 and
5 Out-band Blocking 2230~2255MHz
UE@+20dBm output power(Class3)
-15dBm/3.84MHz@f=1~2025 and
2255~12500MHz
UE@+20dBm output power(Class3)
6Spurious Response
-44dBm CW
UE@+20dBm output power(Class3)
-46dBm CW@10MHz
7Intermodulation Characteristic -46dBm/3.84MHz@20MHz
UE@+20dBm output power(Class3)
-57dBm@f=9KHz~1GHz, 100K BW
8 Spurious Emissions -47dBm@f=1~12.5GHz, 1M BW
-60dBm@f=1920MHz~1980MHz, 3.84M BW
-60dBm@f=2110MHz~2170MHz, 3.84M BW
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2. PERFORMANCE
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2.4 Current Consumption
(Stand by and Voice Call Test Condition : LCD backlight Off)
(VT Test Condition : Speaker off, LCD backlight On)
2.5 Antenna BAR
Stand by (Static) Stand by(Dynamic) Voice Call VT
WCDMA
380hrs (auto mode) 250hrs (auto mode) 140 Min 90 Min
(DRX=2.56) (DRX=2.56) (Tx=10 dBm) (Tx=10 dBm)
Stand By (Static) - Voice Call
260 hrs/260 hrs 200 Min
GSM (auto mode) - (Tx=Max)
(Paging period =5)
Antenna Bar WCDMA GSM
BAR 3 RSCP >= -105 dBm RSSI >= -95 dBm
and Ec/Io >= -10 dBm
BAR 2 -110 <= RSCP < -105 dBm -100 <= RSSI < -95 dBm
or -13 <= Ec/Io < -10 dBm
BAR 1 RSCP < -110 dBm -105 <= RSSI < -100 dBm
or Ec/Io < -13 dBm
Network Notification RSSI < -105 dBm
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2.6 Battery BAR
2. PERFORMANCE
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Indication Voltage
Bar 4 → 3 (68%) Over 3.80 ± 0.05V
Bar 3 → 2 (47%) 3.72 ± 0.05V
Bar 2 → 1 (26%) 3.65 ± 0.05V
Bar 1 → Icon Blinking (5%) 3.47 ± 0.05V
Low Voltage, 3.35 ± 0.05V ([Interval : 30sec(Talk)] - 5%
Warning message+ Blinking 3.32 ± 0.05V ([Interval : 2min(Stand by)] - 3%
Power Off 3.28 ± 0.05V ↓ (else)
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2. PERFORMANCE
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2.7 Sound Pressure Level
2.8 Charging
• Charging Method : CC & CV (Constant Current and Constant Voltage)
• Maximum Charging Voltage : 4.2 V
• Maximum Charging Current : 500 mA
• Normal Battery Capacity : 860 mAh
• Charging Time : Max 3 hours (except for trickle charging time)
• Full charging indication current (charging icon stop current) : 140 mA
• Cut-off voltage : 3.28 V
No Test Item Specification
1 Sending Loudness Rating (SLR) 8 ±3 dB
2 Receiving Loudness Rating (RLR)
Nor -4 ± 3 dB
Max -15 ± 3 dB
3 Side Tone Masking Rating (STMR) Min 17 dB
4 Echo Loss (EL) Min 40 dB
5 Sending Distortion (SD) Refer to Table 30.3
6 Receiving Distortion (RD) Refer to Table 30.4
7 Idle Noise-Sending (INS) Max -64 dBm0p
8 Idle Noise-Receiving (INR)
Nor Under -47 dBPA
Max Under -36 dBPA
9 Sending Loudness Rating (SLR) 8±3dB
10 Receiving Loudness Rating (RLR)
Nor -1 ±3 dB
Max -12 ±3 dB
11 Side Tone Masking Rating (STMR) Min 25 dB
12 Echo Loss (EL) Min 40 dB
13 Sending Distortion (SD) Refer to Table 30.3
14 Receiving Distortion (RD) Refer to Table 30.4
15 Idle Noise-Sending (INS) Max -55 dBm0p
16 Idle Noise-Receiving (INR)
Nor Under -45 dBPA
Max Under -40 dBPA
TDMA Noise
-. GSM : Power Level : 5
DCS/PCS : Power Level : 0
(Cell Power : -90 ~ -105 dBm)
17
-. Acoustic (Max Vol.)
MS/Headset SLR : 8 ±3dB
MS/Headset RLR : -15 ± 3dB/-12dB
(SLR/RLR : Mid-value setting)
MS
Headset
MS and
Headset
Max
Under -62 dBm
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3. TECHNICAL BRIEF
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3.1 General Description
The L602i supports UMTS-2100, UMTS-800 DS-WCDMA, EGSM-900, DCS-1800, and PCS-1900. All
receivers and the UMTS transmitter use the radioOne1Zero-IF architecture to eliminate intermediate
frequencies, directly converting signals between RF and baseband. The EGSM, DCS1800 and
PCS1900 transmitters use a baseband-to-IF upconversion followed by an offset phase-locked loop
that translates the GMSK-modulated signal to RF.
1
QUALCOMM’s branded chipset that implements a Zero-IF radio architecture.
3. TECHNICAL BRIEF
L602i Dual UMTS and quad GSM band functional block diagram
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A generic, high-level functional block diagram of L602i is shown in Figure 1-1. One antenna collects
base station forward link signals and radiates handset reverse link signals. The antenna connects with
receive and transmit paths through a switch module (plus a duplexer for UMTS operation).
UMTS band signals at the antenna are switched to the relevant UMTS duplexer. The UMTS receive
band signals are amplified by the RFL6202 LNA IC before passing through a band-pass filter and
being applied to the mixer inputs of the RFR6202 IC. On-chip circuits down-convert the received signal
directly from RF to baseband using radioOne Zero-IF techniques. The RFR6202 IC outputs analog
baseband signals for processing by the MSM device. This baseband interface is shared with the
RTR6250 GSM receiver outputs, but is separate from the GPS baseband interface.
EGSM, DCS and PCS receive signals from the antenna switch module pass through their band-pass
filters, then are applied to the RTR6250 IC. In a similar fashion to the UMTS paths, RTR6250 IC
circuits down-convert the received signals directly from RF to baseband. The GSM LO for multiband
down conversion is entirely generated within the RTR6250 IC (PLL and distribution functions) with
exception of the off-chip loop filter. The RTR analog baseband outputs are routed to the MSM6250A
IC for further processing (an interface shared with the RFR UMTS receive paths).
The UMTS transmit path begins with analog baseband signals from the MSM device that drive the
RTR6250 IC. Integrated PLL and VCO circuits generate the Tx LO used in the quadrature upconverter
that translates baseband signals directly to RF. The RTR6250 output driver stages deliver fairly highlevel signals that are filtered and applied to the power amplifiers (PA). The PA output is routed to the
antenna through a duplexer and switch module.
The shared EGSM-900, DCS-1800, and PCS-1900 transmit path begins with the same baseband
interface from the MSM6250A IC that is used for the UMTS band. A single EGSM/DCS/PCS
quadrature upconverter translates the GMSK-modulated signal to a convenient intermediate frequency
(IF) that forms one input to an offset phase-locked loop (OPLL). OPLL functions are split between the
RTR6250 IC and off-chip loop filter and dual Tx VCO circuits, and translate the GMSK-modulated
signal to the desired EGSM-900, DCS-1800 or PCS-1900 channel frequency. This signal is applied to
a dual power amplifier (only one is active at a time). The enabled path continues with the PA, an
automated power control (APC) circuit that samples the transmit power and adjusts its level, the switch
module (which includes a band-appropriate lowpass filter), and the antenna.
L602i power supply voltages are managed and regulated by the PM6650 Power Management IC. This
versatile device integrates all wireless handset power management, general housekeeping, and user
interface support functions into a single mixed signal IC. It monitors and controls the external power
source and coordinates battery recharging while maintaining the handset supply voltages using low
dropout, programmable regulators.
The device’s general housekeeping functions include an ADC and analog multiplexer circuit for
monitoring on-chip voltage sources, charging status, and current flow, as well as user-defined off-chip
variables such as temperature, RF output power, and battery ID. Various oscillator, clock, and counter
circuits support IC and higher-level handset functions. Key parameters such as under-voltage lockout
and crystal oscillator signal presence are monitored to protect against detrimental conditions.
3. TECHNICAL BRIEF
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3. TECHNICAL BRIEF
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3.2 GSM Mode
3.2.1 GSM Receiver
The multi-mode L602i’s receiver functions are split between the four RFICs as follows:
• UMTS-800 and UMTS-2100 operation uses the RFL6202 LNA and RFR6202 Receiver ICs to
implement the receive signal path, accepting an RF input and delivering analog baseband outputs (I
and Q).
• EGSM-900, DCS-1800, and PCS-1900 modes both use the RTR6250 IC only. Each mode has
independent front-end circuits and down-converters, but they share common baseband circuits (with
only one mode active at a time). All receiver control functions are beginning with SBI2-controlled
parameters.
The EGSM, DCS, and PCS receiver inputs of RTR6250 are connected directly to the transceiver frontend circuits(filters and antenna switch module). EGSM, DCS, and PCS receiver inputs are similar to
the RFR6202 IC UMTS and GPS mixer input in that they also use differential configurations to improve
common-mode rejection and second-order nonlinearity performance. The balance between the
complementary signals is critical and must be maintained from the RF filter outputs all the way into the
IC pins.
Since EGSM, DCS, and PCS signals are time-division duplex (the handset can only receive or
transmit at one time), switches are used to separate Rx and Tx signals in place of frequency duplexers
- this is accomplished in the switch module.
The EGSM, DCS, and PCS receive signals are routed to the RTR6250 through band selection filters
and matching networks that transform single-ended 50-Ω. sources to differential 100-Ω load
impedances optimized for gain and noise figure. Similar to the RFR, the RTR input uses a differential
configuration to improve second-order intermodulation and common mode rejection performance. The
RTR6250 input stages include MSM-controlled gain adjustments that maximize receiver dynamic
range.
The amplifier outputs drive the RF ports of the quadrature RF-to-baseband downconverters. The
downconverted baseband outputs are multiplexed and routed to lowpass filters (one I and one Q)
having passband and stopband characteristics suitable for GMSK processing.
2
The RFIC operating modes and circuit parameters are MSM-controlled through the proprietary 3-line Serial Bus Interface (SBI). The Application
Programming Interface (API) is used to implement SBI commands. The API is documented in AMSS Software - please see applicable AMSS
Software documentation for details.
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These filter circuits include DC offset corrections. The filter outputs are buffered and passed on to the
MSM6250A IC for further processing (an interface shared with the RFR6202 UMTS receiver outputs).
3. TECHNICAL BRIEF
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3. TECHNICAL BRIEF
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3.2.2 GSM Transmitter
The shared GSM Low-band (EGSM900) and High-band (DCS1800, PCS1900) transmit path begins
with the baseband inputs from the MSM6250A IC. These differential analog input signals are buffered,
lowpass filtered, corrected for DC offsets then applied to the GSM quadrature upconverter. The
upconverter LO signals are generated from the transceiver VCO signal by the LO distribution and
generation circuits within RTR6250.
This upconverter translates the GMSK-modulated signal to a convenient intermediate frequency (IF)
that forms one input to a frequency/phase detector circuit. This IF signal is the reference input to an
offset phase-locked loop (OPLL) circuit as shown in Figure 1.2.2-1.
1. The dual Tx VCO output (operating in the desired RF output frequency range) is buffered within the
RTR6250 IC then applied to the mixer RF port.
2. The LO Generation and Distribution circuits that deliver the transmit path.s LO for the baseband-to-IF
upconversion also provides the .offset LO. signal that is applied to the feedback path.s mixer LO port.
Figure 1.2.2-1 Offset phase-locked loop interfaces
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The mixer IF port output is the offset feedback signal - the variable input to the frequency/phase
detector circuit. The detector compares its variable input to its reference input and generates an error
signal that is lowpass filtered by the loop filter and applied to the dual Tx VCO tuning port to force the
VCO output in the direction that minimizes errors. As mentioned earlier, the VCO output is connected to
the feedback path thereby creating a closed-loop control system that will force frequency and phase
errors between the variable and reference inputs to zero.
The waveform at the dual Tx VCO output is the GMSK-modulated signal centered at the desired GSM
channel frequency. A phase-locked loop circuit is used to translate the GMSK-modulated signal from IF
to RF primarily for two reasons:
1. Phase-locked loops provide a lowpass filter function from the reference input to the VCO output. This
results in a bandpass function centered at the desired channel frequency that provides steep, wellcontrolled rejection of the out-of-band spectrum.
2. The resulting output bandpass function is virtually unchanged as the transmitter is tuned over
channels spanning the GSM operating band.
The PA is a key component in any transmitter chain and must complement the rest of the transmitter
precisely. For GSM band operation, the closed-loop transmit power control functions add even more
requirements relative to the UMTS PA. In addition to gain control and switching requirements, the usual
RF parameters such as gain, output power level, several output spectrum requirements, and power
supply current are critical. The gain must be sufficient and variable to deliver the desired transmitter
output power given the VCO output level, the subsequent passive devices’ losses, and the control set
point. The maximum and minimum transmitter output power levels depend upon the operating band
class and mobile station class per the applicable standard. Transmitter timing requirements and in-band
and out-of-band emissions, all dominated by the PA, are also specified by the applicable standard.
The active dual Tx VCO output is applied to the dual power amplifier to continue the transmit path, and
feedback to the RTR6250 IC to complete the frequency control loop. The PA operating band (EGSM or
DCS/PCS) is selected by the MSM device GPIO control (GSM_PA_BAND).
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3.3 WCDMA Mode
3.3.1 Receiver
The UMTS duplexer receiver output is routed to LNA circuits within the RFL6202 IC. These LNA
functions are removed from the RFR6202 IC to improve mixer LO to RF isolation. The LNA gain is
dynamically controlled by the MSM device to cover full receiver dynamic range and to save current
consumption.
The UMTS LNA output is routed to the RFR6202 through a band selection filter that transforms a
single-ended 50Ω source to differential 100-Ω load impedance that is matched to the RFR6202 IC. The
RFR input uses a differential configuration to improve secondorder inter-modulation and common mode
rejection performance. The RFR6202 IC input stages include MSM-controlled gain adjustments that
further extend receiver dynamic range.
The amplifier output drives the RF port of the quadrature RF-to-baseband down-converter. The downconverted baseband outputs are routed to lowpass filters (one I and one Q) having pass-band and stopband characteristics suitable for DS-WCDMA processing. The filter outputs are buffered and passed on
to the MSM6250A IC for further processing. This baseband interface is shared with the RTR6250 GSM
receiver outputs.
Figure 1.3.1-1 RFL6202 IC functional block diagram
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The RFR6202 IC includes LO generation and distribution circuitry to reduce off-chip component
requirements. The UMTS RX LO source is created using an external UMTS_RX_VCO that is closedloop controlled by the RTR6250 PLL2 via a discrete loop filter, with an RFR6202 buffer amplifier
supplying the PLL feedback signal. When the phone is not in the UMTS800 or UMTS2100 mode the
unused VCO must be turned off by UHF_VCO_0_EN logic signal from MSM6250. Using only the
external UMTS_RX_VCO signal, the LO generation and distribution circuits create the necessary LO
signals for the quadrature downconverter. By definition, the Zero-IF downconverter requires F
LO
equal to
FRF, and the RFR6202 design achieves this without allowing F
VCO
to equal FRF.
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Figure 1.3.1-2 RFR6202 IC functional block diagram
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3.3.2 Transmitter
The UMTS transmit path begins with analog baseband signals from the MSM device that drive the
RTR6250 IC. The RTR6250 IC provides all the UMTS transmitter active signalpath circuits except the
power amplifiers. Analog (I and Q) differential signals from the MSM device are buffered, filtered, and
applied to Baseband-to-RF quadrature upconverters.
Gain control is implemented on-chip. The RF outputs include an integrated matching inductor, reducing
the off-chip matching network to a single series capacitor.
The RTR6250 UMTS output is routed to its power amplifier through a bandpass filter, and delivers fairly
high-level signals that are filtered and applied to the PA. The PA device used in L602i is “Load
Insensitive PA”- no need to use isolator - and routed to the duplexer Tx port directly. Transmit power is
delivered from the duplexer to the antenna through the switch module.
The RTR6250 IC integrates LO generation and distribution circuits on-chip, substantially reducing offchip requirements. Various modes and programmable features result in a highly flexible transceiver LO
output that supports not only UMTS transmissions, but all EGSM900 and DCS1800/PCS1900 Rx and
Tx modes as well.
The UMTS Tx LO (PLL1) is generated almost entirely on-chip, requiring only the loop filter off-chip (two
capacitors and two resistors); all UMTS Tx VCO and PLL circuits are on-chip. An internal RTR6250
switch routes the internal VCO signal to the LO generation and distribution circuits to create the
necessary UMTS Tx LO signals.
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3.4 LO Phase-locked Loop
Most LO functions are fully integrated on-chip, do not require user adjustment, and need not be
considered by handset designers. QUALCOMM has established and implemented frequency plans
and LO generation schemes that support the radioOne 6250-IVseries chipset while requiring minimal
off-chip design effort. Only one area requires handset designer attention: the loop filters of each
phase-locked loop (PLL).
3.4.1 UMTS Receiver LO generation
The UMTS Rx LO functional block are distributed between the RFR6202 IC, RTR6250 IC, and
external UMTS_RX_CH_VCO and loop filter components. The external UMTS_RX_CH_VCO must be
enabled for UMTS Rx operation and disabled otherwise; a dedicated MSM6250 IC signal enables the
VCO.
Most UMTS Rx PLL circuits are included within the RTR6250 IC: reference divider, phase detector,
charge pump, feedback divider, and digital logic that generated LOCK status. The buffered 19.2MHz
TCXO signal provides the synthesizer input (REF), the frequency reference to which the PLL is phase
and frequency locked. The reference is divided by the R-Counter to create a fixed frequency input to
the phase detector, FR. The other phase detector input (FV) varies as the loop acquires lock, and is
generated by dividing the RX_VCO_IN frequency using the feedback path’s N-Counter. The closed
loop will force FV to equal FR when locked. If the loop is not locked the error between FV and FR will
create an error signal at the output of the charge pump.
This error signal is filtered by the loop filter and applied to the VCO, tuning the output frequency such
that the error is decreased. Ultimately the loop forces the error to approach zero and the PLL is phase
and the PLL is phase and frequency locked.
Many key PLL performance characteristics are largely determined by the loop filter designstability,
transitory response, settling time, and phase noise.
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Figure 1.4.1-1 UMTS Rx PLL functional block diagram
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3.4.2 Transceiver PLL (PLL1)
All LO functional blocks for the other handset modes(UMTS Tx, EGSM Tx/Rx, DCS Tx/Rx, PCS
Tx/Rx) are integrated into the RTR6250 IC except the loop filter components (Figure 1.4.2-1). On-chip
circuits include reference divider, phase detector, charge pump, VCO, feedback divider, and digital
logic status. The functional description given in Section 1.4.1 for the UMTS Rx PLL applies to the
Transceiver PLL as well.
The off-chip loop filter allows optimization of key PLL performance characteristics (stability, transitory
response, settling time, and phase noise) for different applications Guidelines are provided in the next
subsection for proper implementation of this critical circuit.
Figure 1.4.2-1 Transceiver PLL functional block diagram
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3.5 Off-chip RF Components
3.5.1 Front End Module(FL1000)
Front End module integrates antenna switch module and GSM Rx filter. The antenna switch module
allows multiple operating bands and modes to share the same antenna. In the L602i design, a
common antenna connects to one of six paths: 1) UMTS-800 Rx/Tx, 2) UMTS-2100 Rx/Tx, 3) EGSM
Rx, 4) DCS-1800 Rx, 5) PCS-1900 Rx, 6)EGSM Tx, and 7) DCS-1800, PCS-1900 Tx. UMTS
operation requires simultaneous reception and transmission, so the UMTS Rx/Tx connection is routed
to a duplexer that separates receive and transmit signals. GSM band of operation is time division
duplexed, so only the receiver or transmitter is active at any time and a frequency duplexer is not
required. The module includes lowpass filters for the GSM bands transmit paths to reduce out-of-band
emissions, PA harmonics in particular.
3.5.2 UMTS duplexer (FL1002, FL1004)
A UMTS duplexer splits a single operating band into receive and transmit paths. Important
performance requirements include:
-. Insertion loss . this component is also in the receive and transmit paths; In the L602i typical losses:
UMTS Tx = 1.5 dB, UMTS Rx = 2.3 dB.
-. Out-of-band rejection or attenuation . the duplexer provides input selectivity for the receiver, output
filtering for the transmitter, and isolation between the two. Rejection levels for both paths are
specified over a number of frequency ranges. Two Tx-to-Rx isolation levels are critical to receiver
performance:
-. Rx-band isolation . the transmitter is specified for out-of-band noise falling into the Rx band. This
noise leaks from the transmit path into the receive path, and must be limited to avoid degrading
receiver sensitivity. The required Rx-band isolation depends on the PA out of-band noise levels and
Rx-band losses between the PA and LNA. Typical duplexer Rx band isolation value is 42 dB.
-. Tx-band isolation . the transmit channel power also leaks into the receiver. In this case, the leakage
is outside the receiver passband but at a relatively high level. It combines with Rx band jammers to
create cross-modulation products that fall in-band to desensitize the receiver. The required Tx-band
isolation depends on the PA channel power and Tx-band losses between the PA and LNA. Typical
duplexer Tx-band isolation value is 50 dB.
-. Passband ripple . the loss of this fairly narrowband device is not flat across its passband. Passband
ripple increases the receive or transmit insertion loss at specific frequencies, creating performance
variations across the band channels, and should be controlled.
-. Return loss . minimize mismatch losses with typical return losses of 10 dB or more (VSWR <2:1).
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3.5.3 UMTS Power Amplifier (U1005, U1007)
The AWT6277 (AWT6307) meets the increasing demands for higher output power in UMTS handsets.
The PA module is optimized for VREF = +2.85 V, a requirement for compatibility with the Qualcomm®
6250 chipset. The device is manufactured on an advanced InGaP HBT MMIC technology offering
state-of-the-art reliability, temperature stability, and ruggedness. Selectable bias modes that optimize
efficiency for different output power levels, and a shutdown mode with low leakage current, increase
handset talk and standby time.
The self-contained 4 mm x 4 mm x 1.1 mm surface mount package incorporates matching networks
optimized for output power, efficiency, and linearity in a 50 Ω system.
3.5.4 Thermistor (R1029)
This thermistor senses temperature variations around UMTS PA to adjust PA gain deviation for assure
compliance with the applicable transmit power control standards. Negative temperature compensation
thermistor is used in the L602i.
Figure1.5.3-1 UMTS PA functional block diagram
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3.5.5 UMTS transmit power detector (U1008)
This detector couples PA output power level to calibrate the transmitter characteristic over the channel
variation and temperature. Its detector coupling range and converted voltage is based on diode
sensitivity and transmitter power level.
The L602i uses National Semiconductor LMV228TLX power detector IC. In Figure 1.5.5-1, Directional
coupler is 20dB. The output voltage is proportional to the logarithm of the input power. Figure1.5.5-2 shows
the output voltage versus PA output power of the LMV228TLX setup as depicted in Figure1.5.5-1
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Figure 1.5.5-1 Block diagram of LMV228TLX Typical Application
Figure 1.5.5-2 Power detector response, Vout vs PA output power
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3.5.6 Dual band GSM power amplifier (U1003)
The SKY77318 Power Amplifier Module (PAM) is designed in a low profile (1.2 mm), compact form
factor for quad-band cellular handsets comprising GSM850/900, DCS1800, and PCS1900 operation.
The PAM also supports Class 12 General Packet Radio Service (GPRS) multi-slot operation.
The module consists of separate GSM850/900 PA and DCS1800/PCS1900 PA blocks, impedancematching circuitry for 50 Ω input and output impedances, and a Power Amplifier Control (PAC) block
with an internal current-sense resistor. The custom BiCMOS integrated circuit provides the internal
PAC function and interface circuitry.
Fabricated onto a single Gallium Arsenide (GaAs) die, one Heterojunction Bipolar Transistor (HBT) PA
block supports the GSM850/900 bands and the other supports the DCS1800 and PCS1900 bands.
Both PA blocks share common power supply pins to distribute current. The GaAs die, the Silicon (Si)
die, and the passive components are mounted on a multi-layer laminate substrate. The assembly is
encapsulated with plastic overmold.
RF input and output ports of the SKY77318 are internally matched to a 50 Ω load to reduce the
number of external components for a quad-band design. Extremely low leakage current (2.5 µA,
typical) of the dual PA module maximizes handset standby time. The SKY77318 also contains bandselect switching circuitry to select GSM (logic 0) or DCS/PCS (logic 1) as determined from the Band
Select (BS) signal. In Figure 1.5.6-1 below, the BS pin selects the PA output (DCS/PCS OUT or
GSM850/900 OUT) and the Analog Power Control (VAPC) controls the level of output power.
The VBATT pin connects to an internal current-sense resistor and interfaces to an integrated power
amplifier control (iPAC™) function, which is insensitive to variations in temperature, power supply,
process, and input power. The ENABLE input allows initial turn-on of PAM circuitry to minimize battery
drain.
Figure 1.5.6-1 GSM PA functional block diagram
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