LG KU730 Service Manual

Date: July, 2006 / Issue 1.0

Service Manual

Model : KU730

Service Manual

KU730

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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 RSSI BAR ..............................................14

2.6 Battery BAR ...........................................14

2.7 Sound Pressure Level............................15

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/MSM6275).........35

3.7 Hardware Architecture ...........................36

3.8 Subsystem(MSM6275) ..........................38

3.9 Power Block ...........................................41

3.10 External memory interface ...................46

3.11 H/W Sub System..................................47

3.12 Main Features ......................................65

4. TROUBLE SHOOTING ...................69

4.1 RF Component.......................................69

4.2 SIGNAL PATH .......................................71

4.3 Checking VTCXO Block.........................73

4.4 Checking Ant. SW Module Block ...........75

4.5. Checking WCDMA Block ......................77

4.6. Checking GSM Block ............................82

4.7 Bluetooth RF Block ................................90

4.8 Power ON Troubleshooting....................93

4.9 Charger Troubleshooting .......................96

4.10 USB Troubleshooting...........................99

4.11 SIM Detect Troubleshooting ..............101

4.12 Key Sense Troubleshooting...............102

4.13 Camera Troubleshooting ...................103

4.14 Keypad Backlight Troubleshooting ....104

4.15 Folder ON/OFF Troubleshooting .......105

4.16 Main LCD Troubleshooting ................106

4.17 Audio Trouble Shooting .....................108

5. DOWNLOAD..................................118

5.1 Introduction ..........................................118

5.2 Downloading procedure .......................118

5.3 Troubleshooting download errors ........129

5.4 Caution.................................................136

6. BLOCK DIAGRAM ........................137

6.1 GSM & WCDMA RF Block...................137

6.2 Interface Diagram ................................139

7. Circuit Diagram ............................143

8. pcb layout .....................................150

9. CALIBRATION ..............................155

9.1 H/W Tool Setup....................................155

9.2 Install & Directory structure..................156

9.3 Others Directory structure of CM_GSM .......157

9.4 Cal. Procedure .............................................158

9.5 just Setting the same....................................159

9.6 Cal. sequence ..............................................159

10. EXPLODED VIEW &

REPLACEMENT PART LIST ..... 161

10.1 EXPLODED VIEW ............................ 161

10.2 Replacement Parts

<Mechanic component>.................... 163

<Main component> ........................... 167

10.3 Accessory ......................................... 184

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 common-carrier
telecommunication service of facilities accessed through or connected to it. The manufacturer will not
be responsible for any charges that result from 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
network, 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

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 GSM900/1800/1900 and WCDMA2100 Folder Handset

Size 96.9 X 49.6 X 19.5mm

Weight 103 g (with Battery)

Power 4.2V Full_chaging, 1050 mAh Li-ion

Talk Time

Over 100 min (WCDMA, Voice)

Over 220 min (GSM, Voice)

Stand by Time

Over 300 Hrs (WCDMA, DRX=1.28)

Over 310 Hrs (GSM, Paging period=5)

Antenna Fixed Type (internal antenna)

LCD TFT Main LCD(2”,176 X 220), STN Sub LCD(1.17”,96 X 96)

LCD Backlight White LED Back Light

Camera Dual camera( 1.3 Mega pixel ,VGA pixel)

Vibrator Yes (Coin Type)

LED Indicator No

C-MIC Yes

Receiver Yes

Earphone Jack Yes (12 pin)

Connectivity Bluetooth, USB

Volume Key Push Type(+, -)

External Memory Micro_SD card

I/O Connect 24 Pin

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 3.7V(Typ), 3.51 V(Min), [Shut Down : 3.28 V]

Operation Temp -20 ~ +60 °C

Storage Temp -30 ~ +85 °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

1 Spurious 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

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

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

8 Transmitter 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

2. PERFORMANCE

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2) Transmitter - WCDMA Mode

No Item Specification

1 Maximum Output Power Class 3 : +24dBm(+1/-3dB)

2 Frequency 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

6 Out-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

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) -105dBm -105dBm

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

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)

2 Maximum 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)

6 Spurious Response

-44dBm CW

UE@+20dBm output power(Class3)

-46dBm CW@10MHz

7 Intermodulation 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

2. PERFORMANCE

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2.4 Current Consumption

(Stand by and Voice Call Test Condition : Bluetooth off, LCD backlight Off)
(VT Test Condition : Speaker off, LCD backlight On)

2.5 RSSI BAR

2.6 Battery BAR

Indication Standby

Bar 4 Over 3.92V

Bar 4 → 3 3.92 ± 0.05V

Bar 3 → 2 3.79 ± 0.05V

Bar 2 → 1 3.71 ± 0.05V

Bar 1 → Empty 3.61 ± 0.05V

Low Voltage, 3.51± 0.05V (Stand-by) / 3.61 ± 0.05V (Talk)

Warning message+ Blinking [Interval : 3min(Stand-by) / 1min(Talk)]

Power Off 3.28 ± 0.05V

Stand by Voice Call VT

WCDMA

Under 8.5 mA Under 450 mA Under 640mA

(DRX=1.28) (Tx=12dBm) (Tx=12dBm)

GSM

Under 6.3 mA Under 380 mA

(Paging=9 period) (Tx=Max)

Level Change WCDMA GSM

BAR 5 Over -85 ± 2 dBm Over -85 ± 2 dBm

BAR 5 → 4 -85 ± 2 dBm -85 ± 2 dBm

BAR 4 → 3 -90 ± 2 dBm -90 ± 2 dBm

BAR 3 → 2 -95 ± 2 dBm -95 ± 2 dBm

BAR 2 → 1 -98 ± 2 dBm -100 ± 2 dBm

BAR 1 → 0 -101 ± 2 dBm -105 ± 2 dBm

2. PERFORMANCE

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2.7 Sound Pressure Level

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

17 (Cell Power : -90 ~ -105 dBm)

-. Acoustic (Max Vol.)

MS/Headset SLR : 8 ±3dB

MS/Headset RLR : -15 ± 3dB/-12 ± 3

(SLR/RLR : Mid-value setting)

MS

Headset

MS and

Headset

Max -62 dBm

2.8 Charging

• Charging Method : CC & CV (Constant Current and Constant Voltage)

• Maximum Charging Voltage : 4.2 V

• Maximum Charging Current : 800 mA

• Normal Battery Capacity : 1050 mAh

• Charging Time : Max 3.0 hours (except for trickle charging time)

• Full charging indication current (charging icon stop current) : 80 mA

• Cut-off voltage : 3.28 V

2. PERFORMANCE

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3. TECHNICAL BRIEF

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3.1 General Description

The KU730 supports UMTS-2100, DS-WCDMA, EGSM-900, DCS-1800, and PCS-1900
GSM/GPRS/EGPRS. All receivers and the UMTS transmitter use the radioOne1 Zero-IF architecture to
eliminate intermediate frequencies, directly converting signals between RF and baseband. The
GSM900, 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

Fig 3.1 Block diagram of RF part

A generic, high-level functional block diagram of KU730 is shown in Figure 3-1. 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 dual band operation).

The UMTS receive signal is amplified by the RFR6250 LNA then passes through a bandpass filter
before being applied to the RFR6250 Receiver IC. On-chip circuits downconvert the received signal
directly from RF to baseband using radioOne Zero-IF techniques. Generation of the UMTS
downconverter LO is distributed between the RTR6250 (phase-locked loop), the RFR6250 (buffer
amplifiers and LO distribution circuits) and external UHF VCO and loop filter circuits. The RFR6250 IC
outputs analog baseband signals for further processing by the MSM device. This baseband interface is
shared with the RTR6250 GSM900 /DCS/PCS receiver outputs.

GSM900, DCS and PCS receive signals pass through their bandpass filters then are applied to the
RTR6250 IC. Similar to the UMTS path, RTR6250 circuits downconvert the received signals directly
from RF to baseband. The GSM900/DCS/PCS downconverter LO is generated mostly within the
RTR6250 (PLL and distribution functions); the UMTS Rx CH VCO and loop filter are off-chip. The RTR
analog baseband outputs are routed to the MSM6275 IC for further processing (an interface shared
with the RFR).

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 GSM-900, DCS-1800, and PCS-1900 transmit path begins with the same baseband
interface from the MSM6275 IC that is used for the UMTS band. A single GSM900/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 GSM-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.

KU730 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 offchip
variables such as temperature, RF output power, and battery ID. Various oscillator, clock, and counter

3. TECHNICAL BRIEF

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3. TECHNICAL BRIEF

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circuits support IC and higher-level handset functions. Key parameters such as undervoltage lockout
and crystal oscillator signal presence are monitored to protect against detrimental conditions.

3.2 GSM Mode

3.2.1 GSM Receiver

The Dual-mode KU730’s receiver functions are split between the three RFICs as follows:

• UMTS-2100 operation uses the RFR6250 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.

RF Front end consists of antenna, antenna switch module(ESHS-L090UB), and three RX saw
filters(GSM, DCS, and PCS). The antenna switch module allows multiple operating bands and modes
to share the same antenna. In KU730, a common antenna connects to one of seven paths: 1)
GSM900 Tx, 2) GSM900 Rxb& WCDMA 3) DCS1800/PCS1900 Tx 4) DCS1800 Rx 5) PCS Rx UMTS
operation requires simultaneous reception and transmission, so the UMTS Rx/Tx connection is routed
to a duplexer that separates receive and transmit signals. GSM900, DCS, and PCS operation is time
division duplexed, so only the receiver or transmitter is active at any time and a frequency duplexer is
not required.

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.

ANT_SEL2 IN_B IN_C

GSM900 TX LOW LOW HIGH

GSM900 RX/WCDMA LOW LOW LOW

DCS1800/PCS1900 TX HIGH HIGH LOW

DCS 1800RX HIGH LOW LOW

PCS 1900RX LOW HIGH LOW

Table. Antenna Switch Module Control logic

The GSM900, DCS, and PCS receiver inputs of RTR6250 are connected directly to the transceiver
front-end circuits (filters and antenna switch module). GSM900, DCS, and PCS receiver inputs are
similar to the RFR6250 UMTS Rx input in that they also use differential configurations to improve
common-mode rejection and second-order non-linearity 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 GSM900, 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 GSM900, 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 impedances optimized
for gain and noise figure. Similar to the RFR, the RTR input uses a differential configuration to improve
second-order inter-modulation 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. These filter circuits
include DC offset corrections.
The filter outputs are buffered and passed on to the MSM6275 IC for further processing (an interface
shared with the RFR6250 UMTS receiver outputs).

3. TECHNICAL BRIEF

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3. TECHNICAL BRIEF

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RTR6250 RX feature

3.2.2 GSM Transmitter

The shared GSM Low-band (GSM900) and High-band (DCS1800, PCS1900) transmit path begins with
the baseband inputs from the MSM6275 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 GMSKmodulated 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 3.2.2-1.

The feedback path of this OPLL circuit includes a downconversion from the RF output frequency range
to the IF range. The two inputs to this downconversion mixer are formed as follows:

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.

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.

3. TECHNICAL BRIEF

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Figure 3.2.2-1 Offset phase-locked loop interfaces

3. TECHNICAL BRIEF

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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 inband
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 (GSM900
or DCS/PCS) is selected by the MSM device GPIO control (GSM_PA_BAND).

3.3 WCDMA Mode

3.3.1 Receiver

The RFR6250 is an RF-to-baseband receiver IC, an integral component of the QUALCOMM 6250­series chipset. All 6250-series ICs are highly integrated and fulfill specific functions; functional
requirements are partitioned between the ICs to yield complete, optimal transceiver implementations.
Overall radio performance depends on the combined, complementary performance of all the ICs in the
chipset.
The RFR6250 IC (Figure3.3.3-1) provides the zero-IF receiver signal path, from RF to analog
baseband, for UMTS-1900, UMTS-2100 and GPS applications. The RFR6250 zero-IF architecture and
highly integrated implementation reduce handset PCB size and material costs.

The QUALCOMM RFR6250 IC is a custom GPS/UMTS-band design that meets DSWCDMA dynamic
range requirements.
The RFR6250 IC accepts its UMTS-1900, UMTS-2100 and GPS input signals from the handset RF
front-end filters. Each individual input is provided with an on-chip LNA that amplifies the signal before a
second stage filter that provides differential downconverter. This second stage input is configured
differentially to optimize second-order inter-modulation and common mode rejection performance.
The gains of the UMTS front-end amplifiers and the UMTS second stage differential amplifiers are
adjustable, under MSM. control, to extend the dynamic range of the receivers.
The second stage amplifiers drive the RF ports of the quadrature RF-to-baseband downconverters.
As only one UMTS path will be in operation at any one time, the outputs of the second stage amplifiers
are switched, as required, to drive the RF ports of the quadrature RF-tobaseband down-converters,
while the GPS receiver has its own dedicated down-converter to allow it to operate simultaneously.

3. TECHNICAL BRIEF

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Figure 3.3.3-1 RFR6250 IC Fuctional block diagram

3. TECHNICAL BRIEF

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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 signal-path 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 CU320 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 GSM850900 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.

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-IIseries 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 Rx PLL (PLL2)

UMTS Rx LO functional blocks are distributed between the RFR6202 IC, RTR6250 IC, and external
UMTS_RX_CH_VCO and loop filter components (Figure 3.4.1-1).
The external UMTS_RX_CH_VCO must be enabled for UMTS Rx operation and disabled otherwise; a
dedicated MSM6275 IC signal (UHF_VCO_EN ) enables the VCO.

The RFR6250 IC accommodates single-ended or differential LO inputs; if singleended, either pin can
be active. AC-couple the inactive pin to ground using an appropriately valued capacitor (4 pF is used
in KU730). The 27 pF capacitor should be used to AC-couple the active pin to the VCO signal. Using
only the selected VCO signal, the RFR6250 IC LO generation and distribution circuits create the
necessary LO signals for the active quadrature downconverter.

A sample of the downconverter LO is buffered and routed from RFR6250 IC pin 28 to RTR6250 IC pin
32 (RX_VCO_IN). This signal requires a terminating resistor near the RTR6250 IC input pin and an AC
coupling capacitor that assures the internal RTR6250 IC biasing is not disrupted in the example. Good
microstrip or stripline controlled-impedance techniques must be used.

3. TECHNICAL BRIEF

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Figure 3.4.1-1 UMTS Rx PLL functional block diagram

3. TECHNICAL BRIEF

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Most UMTS Rx PLL circuits are included within the RTR6250 IC: reference divider, phase detector,
charge pump, feedback divider, and digital logic that generate LOCK status. The buffered 19.2 MHz
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 frequency locked.

Many key PLL performance characteristics are largely determined by the loop filter design - stability,
transitory response, settling time, and phase noise.

3.4.2 Transceiver PLL (PLL1)

All LO functional blocks for the other handset modes(UMTS Tx, GSM850 Tx/Rx, DCS Tx/Rx, PCS
Tx/Rx) are integrated into the RTR6250 IC except the loop filter components (Figure 3.4.2-1). On-chip
circuits include reference divider, phase detector, charge pump, VCO, feedback divider, and digital
logic status. The functional description given in Section 3.4.1 for the UMTS Rx PLL applies to the
Transceiver PLL as well.

Figure 3.4.2-1 Transceiver PLL functional block diagram

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.

3.5 Off-chip RF Components

3.5.1 Antenna switch module (FL100 : ESHS-L090UB)

The antenna switch module allows multiple operating bands and modes to share the same antenna. In
the KU730 design, a common antenna connects to one of five paths: 1) GSM900 TX 2)
GSM900RX/WCDMA 3) DCS1800/PCS1900TX 4) DCS1800 RX 5) PCS1900 Rx 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 (FL103 : ACMD7601 )

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 KU730 typical losses
: UMTS Tx = 1.2 dB, UMTS Rx = 1.6 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. Minimum duplexer Rx band isolation value is about 48dB.

-. 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. Minimum
duplexer Tx-band isolation value is about 51dB.

-. 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.s channels, and should be controlled.

3. TECHNICAL BRIEF

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3. TECHNICAL BRIEF

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-. Return loss . minimize mismatch losses with typical return losses of 10 dB or more (VSWR <2:1).

-. Power handling . high power levels in the transmit path must be accommodated without degraded
performance. The specified level depends on the operating band class and mobile station class (per
the applicable standard), as well as circuit losses and antenna EIRP. Several duplexer
characteristics depend upon its source and load impedances. QUALCOMM strongly recommends an
isolator be used between the UMTS PA and duplexer to assure proper performance.

3.5.3 UMTS Power Amplifier (U103)

-. U103 : WCDMA2100 Power Amplifier module

The SKY77410 Load Insensitive Power Amplifier (LIPATM) module is a fully matched 16-pin surface
mount module developed for Wideband Code Division Multiple Access (WCDMA) applications. This
small and efficient power amplifier packs full coverage of the 1850-1980 MHz bandwidth into a single
compact package.

SKY77410 meets the stringent spectral linearity requirements of WCDMA transmission with high
power added efficiency for power output of up to 28 dBm, even with a load mismatch of 4:1 VSWR ­eliminating the need for an isolator. A low current (VCONT) pin provides improved operating efficiency
in the low RF power range. To further improve efficiency in this range, a separate VBIAS pin can be
directly connected to the battery, which allows reducing VCC1 and VCC2 voltages to 0.8 V to achieve
very low power consumption.

The single Gallium Arsenide (GaAs) Microwave Monolithic Integrated Circuit (MMIC) contains all
active circuitry in the module. The MMIC contains on-board bias circuitry, as well as input and
interstage matching circuits. The output match is realized off-chip within the module package to
optimize efficiency and power performance into a 50 Ω load. This device is manufactured with
Skyworks’ GaAs Heterojunction Bipolar Transistor (HBT) process that provides for all positive voltage
DC supply operation while maintaining high efficiency and good linearity.
Primary bias to the SKY77410 is supplied directly from a three-cell Ni-Cd, a singlecell Li-Ion, or other
suitable battery with an output in the 3.2 to 4.2 volt range. Power down is accomplished by setting the
voltage on the low current reference pin to zero volts. No external supply side switch is needed as
typical “off” leakage is a few microamperes with full primary voltage supplied from the battery.

The directional coupler provides RF input signal into the duplexer and coupled signal into the HDET at
the same time. this protects interference between the duplexer and the HDET and improves PA
stability, ACPR performance, and harmonic suppression, as well as duplexer isolation, insertion loss
and ripple. Transmitter performance is always improved when a coupler is included and is well worth
the added cost.

3.5.4 Thermistor (R140 : 68K_2012_10%)

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 KU730.

3. TECHNICAL BRIEF

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Figure 3.5.3-1 UMTS PA functional block diagram

3. TECHNICAL BRIEF

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3.5.5 UMTS transmit power detector (U105 : ADL5500)

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. ADL5500 is a mean-responding power detector for use in high
frequency receiver and transmitter signal chains from 100 MHz to 6GHz. It is easy to apply, requiring
only a single supply between 2.7V and 5.5V and a power supply decoupling capacitor. The input is
internally ac coupled and has a nominal input impedance of 50 Ohm. The output is a linear-responding
dc voltage with a conversion gain of 6.4V/Vrms at 900MHz. The on chip, 1kohm series resistance at
the output with an external shunt capacitor creates a low-pass filter response that reduce the residual
in the dc output voltage.

The ADL5500 is intended for true power measurement of simple and complex waveforms. The device
is particularly useful for measuring high crest factor (high peak-to-rms)signals, such as
CDMA,WCDMA and QPSK/QAM based OFDM waveforms. The KU730 uses ADL5500 power detector
IC. In Figure 3.5.5-1, Figure3.5.5-2 shows the output voltage versus PA output power of the ADL5500
setup as depicted in Figure3.5.5-1

Figure 3.5.5-1 Block diagram of ADL5500

Figure 3.5.5-2 Power detector response, Vout vs PA output power