CUTE-FRIME Service Manual
CUTE-FRIME
CUTE-FRIME Service Manual
(GSM,DCS Cellular Phone)
Pantech Co., Ltd., Korea
January 21, 2025
1st Edition
For Use by Authorized Service/Maintenance Personal Only
Documents to Receive This Addendum:
CUTE-FRIME Maintenance/Repair/Operating Manual
CUTE-FRIME Service Manual
1
CONTENTS
SECTION 1 INTRODUCTION ............................................................................................................. 3
1.1 INTRODUCTION .............................................................................................................................. 3
1.2 FREQUENCY ALLOCATION AND ITS USE ........................................................................................... 3
1.3 ITEM NAME AND USE ...................................................................................................................... 4
1.4 CHARACTERISTICS ......................................................................................................................... 4
SECTION 2 ELECTRICAL SPECIFICATIONS .................................................................................... 5
2.1 GENERAL ...................................................................................................................................... 5
2.2 TRANSMITTER…………………………………………………………………………………………….5
2.3 RECEIVER…………………………………………………………………………………………………5
SECTION 3 OPERATION .................................................................................................................... 6
3.1 NAME OF EACH PART…..……………………………….…………………………………………………6
3.2.DISPLAY ..………………….…………………………….………………………………………………..7
3.3 KEYPAD …………………………………….………….………………………………………………..7
SECTION 4 THEORY OF OPERATION .............................................................................................. 8
4.1 LOGIC SECTION ........................................................................................................................ 8
4.1.1 DC DISTRIBUTION AND REGULATION PART…………………………………………………………….8
4.1.2 LOGIC PART…………………………………………………………………………………………….8
4.1.2.1 SUMMARY…………………………………………………………………………………………….8
4.1.2.2 BASEBAND DIGITAL SIGNAL PROCESSING…………………………………………………………..8
4.1.3 MEMORY PART………………………………………………………………………………………..10
4.1.4 NOTIFICATION PART .................................................................................................................. 11
4.1.5 KEY PAD PART .......................................................................................................................... 11
4.1.6 LCD MODULE(DISPLAY PART) ................................................................................................... 11
4.2 RADIO TRANSCEIVER SECTION ..................................................................................................... 12
4.2.1 DC DISTRIBUTION AND REGULATION PART ................................................................................. 13
4.2.2 TRANSCEIVER PIN DESCRIPTION…………………………………………………….……….14
4.2.3 RECEIVE SECTION………………………………………………………………………………….…17
4.2.3.1 AN OVERVIEW OF RECEIVE SECTION ....................................................................................... 17
4.2.3.2 RECEIVER PART……………………………………………………………………………….……18
4.2.4 TRANSMIT SECTION .................................................................................................................. 19
4.2.4.1 AN OVERVIEW OF TRANSMIT SECTION .................................................................................... 19
4.2.4.2 TRANSMITTER PART ............................................................................................................... 20
4.2.5 OFFSET PLL……………………………………………………………………………….…………..21
4.2.5.1 AN OVERVIEW OF OFFSET PLL ............................................................................................ 21
4.2.5.2 VCTCXO(VOLTAGE CONTROLLED TEMPERATURE COMPENSATED CRYSTAL OSCILLATOR):V801….22
SECTION 5 ALIGNMENT PROCEDURE .......................................................................................... 23
5.1 RECOMMENDED TEST EQUIPMENT ................................................................................................ 23
5.2 CONNECTION OF TEST EQUIPMENT ............................................................................................... 23
SECTION 6 EQUIPMENT REPAIR PROCEDURE ........................................................................... 24
6.1 NO POWER ON WITH BATTERY APPLIED .......................................................................................... 24
6.1.1 POWER CHECK ......................................................................................................................... 24
6.1.2 OSCILLATION CHECK ................................................................................................................ 29
6.1.3 KEYPAD LED NOT IN OPERATION(BLUE) ..................................................................................... 30
6.1.4 LCD EL BACKLIGHT LED NOT IN OPERATION(WHITE)..………………………………………… …32
6.1.5 POWER INDICATED LED & STATUS LED ...................................................................................... 32
6.2 AUDIO PART(EARPIECE, HANDS FREE EARPHONE, MICROPHONE, HANDS FREE MIC) .................. 34
6.2.1 NO RECEIVING TONE HEARD (EARPIECE) .................................................................................. 34
6.2.2 NO RECEIVING TONE HEARD (HANDS FREE EARPHONE) ............................................................. 34
6.2.3 SIDETONE NOT TRANSMITTED (EARPIECE) ................................................................................ 37
6.2.4 SIDETONE NOT TRANSMITTED (HANDS FREE MIC) ..................................................................... 37
6.2.5 HOOK SWITCH NOT WORKING ................................................................................................ 39
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
2
6.2.6 MELODY NOT RINGING ........................................................................................................... ..40
6.2.7 VIBRATOR NOT WORKING …………………………………………………………………...…41
6.3 SIM CARD PART ……………………………………...…………………………………………….42
6.3.1 SIM ERROR ………………………………………………………………………………………….42
6.4 CHARGER PART……………………………………………………………………………………..43
6.4.1 CHARGING ERROR ………………………………..…………………………………………………43
6.5 RF PART…………….………………………………………………………………………………… 45
6.5.1 TEST CONDITIONS………………………………………………………………… …………………45
6.5.2 POWER SUPPLY CHECK POINT……………………………………………………………………….46
6.5.3 POWER AMPLIFIER MODULE ………………………………………………………………………...49
6.5.4 VCTCXO...…………...………………………………………………………………………………..51
6.5.5 ANTENNA SWITCH MODULE……………………………………………………….…………………..53
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
3
For standard GSM Fl(n)=890+0.2*n 1 ≤n≤ 124 Fu(n)=Fl(n)+45
890 MHz ~915 MHz : Mobile Transmit,Base receive
935 MHz ~960 MHz : Base Transmit, Mobile receive
For Extended GSM Fl(n)=890+0.2*n 1 ≤n≤ 124 Fu(n)=Fl(n)+45
Fl(n)=890+0.2*(n-1024) 975 ≤n≤ 1023
880 MHz ~915 MHz : Mobile Transmit,Base receive
925 MHz ~960 MHz : Base Transmit, Mobile receive
For DCS Band Fl(n)=1710.2+0.2*(n-512) 512 ≤n≤ 885 Fu(n)=Fl(n)+95
1710 MHz ~1785 MHz : Mobile Transmit,Base receive
1805 MHz ~1880 MHz : Base Transmit, Mobile receive
SECTION 1. Introduction
1.1 An Introduction of GSM Digital Cellular Mobile Communication System
GSM (Global System for Mobile communication) concluded that digital technology working in
the Time Division Multiple Access (TDMA) mode would provide the optimum solution for the
future system. Specifically , a TDMA system has the following advantage
► Offers a possibility of channel splitting and advanced speech coding ,resulting in improved
spectrum efficiency.
► Offers much greater variety of service than the analog
► Allows considerable improvements to be made with regards to the protection of information.
The GSM system is basically designed as a combination of three major subsystem;
The network subsystem, the radio subsystem, and the operation support system.
The functional architecture of a GSM system can be divided into the Mobile Station (MS), the Base
Station (BS), and the Network Subsystem (NS). The MS is carried by the subscriber, the BS
subsystem controls the radio link with the MS and the NS performs the switching of calls between
the mobile and other fixed or mobile network users as well as mobility management. The MS and
the BS subsystem communicate across the Um interface also known as radio link
The specifications relating to MS are as follows:
TS 100 607-1 : Digital cellular telecommunication system(Phase2+)Mobile Station (MS) con
Formance specification Part1:Conformance specification
1.2 Frequency Allocation and Its Use
Transmit frequency band : 880 MHz ~ 915 MHz(For EGSM) , 1710 MHz ~ 1785 MHz(For DCS)
Receive frequency band: 925 MHz ~ 960 MHz(For EGSM) , 1805 MHz ~ 1880 MHz(For DCS)
Channel spacing : 200KHz
ARFCN(Absolute Radio Frequency Channel Number) : 1~124 and 975~1023 (For EGSM),
512~885(For DCS)
Transmit·receive frequency spacing: 45 MHz
Frequency band and Channel Arrangement
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
4
** Fl(n)= frequency value of the carrier , Fu(n)= corresponding frequency value in upper band
1.3 Item Name and Use
CUTE-FRIME, GSM digital cell phone, is supercompact, superlight mobile communication terminal
for personal use. It has a 900MHz and 1800MHz frequency band and adopts GSM and DCS mode
having excellent spectrum efficiency, economy, and portability.
This product is GSM Cellular type portable phone, adopting 1-cell Li-ion battery and power saving
circuit to maximize its operation time. Also, it is equipped with a fixed snap-in antenna and its color
LCD with font built in enables both Chinese and English text service. And power control(basic
feature of GSM), security feature, voice symbol feature, and variable data rate feature are used
appropriately to ensure its best performance. This product consists of a handset, battery pack, and
Travel charger.
1.4 Characteristics
1) All the active devices of CUTE-FRIME are made of semiconductors to ensure excellent
performance and semi-permanent use.
2) Surface mounting device(SMD) is used to ensure high reliability and compactness/lightness.
3) CUTE-FRIME adopts the Silabs’s AERO RF transceiver, which is CMOS RF front-end for
multi-band GSM digital cellular handsets. The Aero's highly-integrated architecture eliminates
the IF SAW filter, low noise amplifiers (LNAs) for three bands, transmit and RF voltage-controlled
oscillator (VCO) modules, and more than 60 other discrete components found in conventional
GSM handsets to deliver smaller, more cost effective GSM solutions that are easier to design
and manufacture.
4) CUTE-FRIME is designed to perform excellently even in the worst environment.
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
5
Mobile Transmit Frequency
880 MHz ~ 915 MHz/1710MHz ~ 1785MHz
Mobile Receive Frequency
925 MHz ~ 960 MHz/1805MHz ~ 1880MHz
The Number of Time Slot
8
The Number of Channels
174/375
Channel Spacing
200 kHz
Power Supply
Rechargeable Li-Ion Battery 3.7V/670mAH,960mAH
Operating Temperature
-10℃ ∼ +55℃
Dimension
83.3(H) ×45.4(W) ×20.5(D) mm (SLIM)
Weight
84.4 g
Maximum Output Power
33±2 / 30±2 dBm
Frequency Error
±90Hz/±180Hz
Phase Error
RMS < 5°, PEAK < 20°
Minimum Output Power
5±5 / 0±5 dBm
Power Control
5~19(2dB Step)/0~15(2dB Step)
Output RF Spectrum
TS 100 910V6.2.0
Switching Transient
TS 100 910V6.2.0
Intermodulation attenuation
Conducted Spurious Emissions
Idle Mode
-57dBm 9KHz~880M/915MHz~1GHz
-59dBm 880MHz~915MHz
-53dBm 1.7~1.785GHz
-47dBm 1~1.715GHz/1.785GHz~12.75GHz
Allocated Channel
-36dBm 9KHz~ 1GHz
-30dBm 1GHz~ 12.75GHz
Reference Sensitivity
For GSM900 small MS :-102dBm
For DCS1800 class3 MS : -102dBm
For Adjacent interference
For Adjacent(200KHz) interference
For Adjacent(400KHz) interference
For Adjacent(600KHz) interference
C/Ic
9Db
C/Ia1
-9dB
C/Ia2
-41dB
C/Ia3
-49dB
Section 2. Electrical Specifications
2.1 General E-GSM / DCS
2.2 Transmitter E-GSM / DCS
2.3 Receiver
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
6
ANTENNA
SUB LCD
7COLOR LED
SPEAKER
EARPIECE
MAIN LCD
SIDEKEY
KEYPAD
Section 3 Operation
3.1 Name of each part
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
7
Parameter
Projected Actual(MAIN LCD)
Display
Color STN LCD with white LED back lighting
65536 colors
European Character : (font size : 1616) 6 lines x 16
characters
Chinese Character : (font size : 1616) 6 lines 7
characters
Driver
HD66766(Hitachi)
Module Dimen.
36.5(W) x 49.6(H) x 4.75(D)
View size
28.0(W) x 31.4(H)
Active Area
24.561(W) x 28.442(H)
Dot size
0.049(W) x 0.184(H)
Dot pitch
0.064(W) x 0.199(H)
Parameter
Projected Actual(SUB LCD)
Display
Full Graphic LCD with white LED back lighting
Pixels : 96 x 48
European Character : (font size : 715) 1 lines x 12
characters
Chinese Character : (font size : 1616) 1 lines 6
characters
Driver
S1D10606(Seiko epson)
Module Dimen.
36.5(W) x 49.6(H) x 4.75(D)
View size
21.34(W) x 11.825(H)
Active Area
18.705(W) x 9.825(H)
Dot size
0.18(W) x 0.19(H)
Dot pitch
0.195(W) x 0.205(H)
Market Goal
Projected Actual
Comments
English
Keypad
0-9, *,#
Send (Color)
End/Pwr (Color)
Up, Down
Soft1, Soft2, CLR
* Key: Vib. Mode
# Key: Auto Lock
0/+Key: nternational
2 Volume Keys
0-9, *,#
Send (Color)
End/Pwr (Color)
Up, Down
Soft1, Soft2, CLR
* Key: Vib. Mode
# Key: Auto Lock
0/+ Key: International
2 Volume Keys
Meets Goal.
(Industrial
design sample
required)
Meets Goal
Keys for VR and
Lock
International
Volume
up/down
3.2 Display(Dual LCD)
3.3 Keypad
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
8
Section 4. Theory of Operation
4.1 Logic Section
4.1.1 DC Distribution and Regulation Part
Applying battery voltage and pressing “END” key on the key pad short-circuits “Ground” and “_
PowerON”.ADP3408(U104)control that power manage regarding power on/off in handset
Pressing POWERKEY on the key pad is active on the handset.
This will turn on all the LDOs ,when POWERKEY is held low. The power of RF Tx power amplifier is
supplied directly by the battery.
4.1.2 Logic part
4.1.2.1 Summary
The logic part consists of AD6522 ARM7 microprocessor-combined GSM-ASIC, COMBO(flash
ROM & SRAM), AD6521 VBC Chip. AD6522 is GSM-ASIC chipset implemented for GSM terminal’s
system control and baseband digital signal processing.
Major parts used in the logic part are as follows:
1) AD6522 : U101, [ARM7 Processor Core + GSM Signal Processing] ASIC
2) AD6521 : U102, Voiceband Baseband Codec
3) COMBO MEMORY(Flash ROM : U105, 128Mbit Flash Memory + 32Mbit SRAM )
4.1.2.2 Baseband Digital Signal Processing
AD6522 is a GSM core device containing ARM7 CPU core. AD6522 is 160 pin PBGA package,
consisting of terminal chips. The function and characteristics of clock are as follows:
1) Complete single chip GSM Processor
2) Channel codec sub-system
• Channel coder and decoder
• Interleaver and Deinterleaver
• Encryption and Decryption
3) Control Processor Subsystem including
• Parallel and serial Display interface
• Keypad Interface
• SIM Interface
• Control of RADIO subsystem
• Real Time Clock with Alarm
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
9
☞ Configuration by Function of AD6522
1 Microprocessor Core
AD6522 has a built-in ARM7 microprocessor core, including microprocessor interrupt controller,
timer/counter, and DMA controller. And besides, 32bit data path is included, and up to 8Mbyte
addressing is enabled and can be extended up to 16Mbyte. Although external clock should be
provided to operate the microprocessor, this core uses 13MHz VCTCXO to provide clock.
2 Input Clock
1) Main Clock(13 MHz):
This is the clock needed for the microprocessor built in AD6522 to operate.
2) VC-TCXO(13 MHz) , 32.768KHz Clock:
This is the system reference clock to control SLEEP mode.
This is the clock derived from 13MHz VC-TCXO clock, provided by RF part. It is the timing
reference clock for GSM signal processing.
3 DSP Subsystem
This is a GSM signal processing part in GSM mode, consisting of speech transcoding and
Channel equalization as follows:
1) Speech transcoding
In full rate, the DSP receives the speech data stream from VBC and encodes data from
104kbps to13kbps. Using algorithm is Regular Pulse Excitation with Long Term Prediction
(RPE-LTP).
2) Equalization
The Equalizer recovers and demodulates the received signal
The Equalizer establishes local timing and frequency references for mobile terminal as well
as RSSI calculation.
The equlization algorithm is a version of Maximum Likelihood Sequency Estimation(MLSI)
using Viterbi Algorithm.
☞ GSM Core와 RF Interface
1) Transmitter:
AD6521 VBC receive data at 270kbps and use an on chip lock-up table to perform GMSK
modulation. A pair of 10bit matched differential DACs convert the modulated data and pass
I and Q analog data to the transmit section of the radio system.
2) Receiver:
The receiver I and Q signals are sampled by a pair of ADCs at 270kbps.
The I and Q samples are transferred to the EGSMP through a dedicated receive path serial port.
4 RF Interface
This interfaces the RF part to control power amplifier, Tx LO buffer amplifier, VC-TCXO, and
AGC-end on transmit/receive paths in the RF part.
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
10
1) Transmitter Interface:
This transmits TX_AGC signal to Tx AGC amplifier to adjust transmit power level and sends
Ramp_DAC signal to the RF part to control power amplifier.
2) Receiver Interface:
This transmits RX_AGC signal to Rx AGC amp. to adjust receive path gain.
5 General Purpose ADC Support
The AD6521 includes a general purpose 10bit auxiliary ADC with four multiplexed input channel
These are used for measurment of battery voltage ID , temperature and accessory ID.
6 USC(Universal System Connector) Interface
A Typical GSM handset requires serial connections to provide data during normal phone operation
manufacturing,testing and debugging.
7 General Purpose Interface
The AD6522 provides 32 interface pin for control of peripheral devices.
All GPIO pins start up as inputs. Additional purpose inputs and outputs are available under SW
control.
8 Speech Transcoding
In full rate mode, the DSP receive the speech data stream from the VBC and encodes data from
104kbps to 13kbps.Using algorithm is Regular Pulse Exitation with Long Term Prediction as
specified GSM Recommandation
9 Power Down Control Section
1) Idle Mode Control: If IDLE/ signal turns ‘Low’, transmitter section becomes disabled.
2) Sleep Mode Control: If IDLE/ and SLEEP/ signals turn ‘Low’, all the sections except for VC-TCXO circuit become
disabled.
3) Receiver & Transmitter Mode Control: If IDLE/ and SLEEP/ signals turn ‘High’, all the sections become enabled to perform transmit/receive operation.
4.1.3 Memory Part
Memory consists of COMBO(flash ROM & SRAM).
1 Flash ROM
Flash ROM has a capacity of 128Mbit(16MByte). The main programs of the terminal(call processing,
user interface, and diagnostic task) and supplemental programs(NAM program and test program)
are stored in the flash ROM. Even if the program version may be changed in the future, customers
can download the program.
2 Static RAM
SRAM has a capacity of 32Mbit(4MByte) and stores system parameters, data buffer, and stack of
each task in it.
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
11
3 Key Tone Generation
All alert signals are generated by the DSP and output to the EVBC.
These alert can be used for the earpiece.
4.1.4 Notification Part
The notification of incoming call is given by melody, vibrator, and 7color-LED.
1) Melody:
This is a device sounding alert/melody tones.
The melody datas are stored in flash memory(U105) And generated by Melody IC(U108).
2) Vibrator:
This is a device enabling vibration. The vibrator data is stored in flash memory(U105)
And generated by C5(GPO_23)pin.
3) 7color-LED:
This is a device to indicate a notification mode using the lamp.
U101 Nos. A10, A9 and B12 signal drives the lamp to flash.
4.1.5 Key Pad Part
To enable key operation to input information, the key matrix is configured using strobe signal of
KEYPADROW(0-4) and 5 input ports of KEYPADCOL(0-4). Also, to use the key even at light, the
backlight circuit is provided for LED 12.
4.1.6 LCD Module(Display Part)
LCD module consists of LCD , controller, LED-Backlight, and LCD reflector.using dual LCD
Main LCD: 1S/W Icon x 6 lines[(128x3)x128] can be displayed on the LCD panel. 6 icons could be
provided by S/W. Controller with English font built in has been used.
Sub LCD: 1S/W Icon x 1 lines(96x48) can be displayed on the LCD panel. 6 icons are provided.
Controller with English font built in has been used.
LED-backlight Using illuminates the LCD panel, and LCD reflector enhances LCD display effect.
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
12
4.2 Radio Transceiver Section
Fig.4-1. RF Transceiver block diagram
Fig.4-2. Top view of RF Transceiver PCB Layout
The CUTE-FRIME’s RF Transceiver, which is AERO, consists of the Si4200 GSM transceiver
(U710), Si4201 universal baseband interface (U702), and Si4133T dual RF synthesizer (U601).
The highly integrated solution eliminates the IF SAW filter, external low noise amplifiers (LNAs) for
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
13
three bands, transmit and RF voltage controlled oscillator (VCO) modules, and more than 60 other
discrete components found in conventional designs.
The receive section uses a digital low-IF architecture that avoids the difficulties associated with
direct conversion while delivering lower solution cost and reduced complexity. The universal
baseband interface (U702) is compatible with any supplier’s baseband subsystem.
The transmit section is a complete up-conversion path from the baseband subsystem to the power
amplifer (U701) and uses an offset phase locked loop (PLL) with a fully integrated transmit VCO.
The frequency synthesizer (U601) includes integrated RF and IF VCO’s, Varactors, and Loop filters.
The unique integer-N PLL architecture used in the Si4133T (U601) produces a transient response
that is superior in speed to fractional architectures without suffering the high phase noise or
spurious modulation effects often associated with those designs.
The following Figure shows CUTE-FRIME’s top view of PCB artworks.
4.2.1 DC Distribution and Regulation Part
The battery voltage, in return, is applied to the logic part and RF part via LDO(Low Drop-Out)
regulator. As several LDO regulators are used, power can be supplied for each necessary part
efficiently. Audio/Logic parts use +2.8V. RF parts such as U702(Si4201 universal baseband
interface), U710(Si4200 GSM Transceiver) and U601(Si4133T Dual RF synthesizer) also use
+2.8V DC voltage.
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
14
4.2.2 Transciever pin description
Fig.4-3. Top View of Si4200DB-BM
Table 4-1. Pin Description of Si4200DB-BM
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
15
Fig.4-4. Top View of Si4201-BM
Table 4-2. Pin Description of Si4201-BM
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
16
Fig.4-5. Top View of Si4133T-BM
Table 4-3. Pin Description of Si4133T-BM
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
17
4.2.3 Receiver Section
4.2.3.1 An Overview of Receive section
Fig.4-6. Receiver block diagram
The CUTE-FRIME model’s Aero transceiver uses a low-IF receiver architecture that follows for the
on-chip integration of the channel selection filters, eliminating the external RF image reject filters
and the IF SAW filter required in conventional superheterodyne architectures. Compared to a direct
conversion architecture, the low-IF architecture has a much greater degree of immunity to dc
offsets that can arise from RF local oscillator (RFLO) self-mixing, 2nd order distortion of blockers,
and device 1/f noise. This relaxes the common-mode balance requirements on the input SAW filters
and simplifies PC board design and manufacturing.
The Si4200 integrates three differential-input LNAs( At CUTE-FRIME, we only used two inputs that
are EGSM and DCS). The GSM input supports EGSM 900 (925– 960 MHz) band. The DCS input
supports the DCS 1800 (1805 – 1880 MHz).
A quadrature image-reject mixer downconverts the RF signal to a 100 kHz intermediate frequency
(IF) with the RFLO from the Si4133T frequency synthesizer. The RFLO frequency is between
1737.8 and 1989.9 MHz, and is divided by two in the Si4200 for GSM 850 and EGSM 900 modes.
The mixer output is amplified with an analog programmable gain amplifer (PGA), which is controlled
with the AGAIN[2:0] bits in register 05h. The quadrature IF signal is digitized with high resolution
A/D converters (ADCs).
The Si4201 downconverts the ADC output to baseband with a digital 100 kHz quadrature LO signal.
Digital decimation and IIR filters perform channel selection to remove blocking and reference
interference signals. After channel selection, the digital output is scaled with a digital PGA, which is
controlled with the DGAIN[5:0] bits in register 05h.
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
18
These analog and digital gain resigters must be set to provide a constant amplitude signal to the
baseband receive inputs.
DACs drive a differential analog signal onto the RXIP,RXIN,RXQP and RXQN pins to interface to
standard analog-input baseband Ics.
4.2.3.2 Receiver Part
A. Diplexer: Z701
This consists of Tx filter, having an antenna port, and of dual configuration with the transmitting path
isolated from the receiving path. A signal received from the antenna to frequency band of 942.5±
17.5MHz for EGSM bands, 1842.5±37.5 MHz for DCS bands and transmits it to dual saw filter. The
Tx filter filters an output signal from the power amplifier to frequency band of 897.5MHz ±17.5MHz
for EGSM bands, 1747.5 ±37.5 MHz for DCS bands and transmits it to the antenna. The maximum
insertion loss is about 0.8 dB for the receiving bands at 25o C and about 1.35 dB for the transmitting
bands at 25o C.
B. SAW filter (BPF / Band select filter): Z510, Z511
The Z510 filter only passes for the EGSM bands which is 942.5±17.5MHz. And the Z511 filter pass
bands are only for DCS bands that is 1842.5 ±37.5MHz.
These filters eliminate other signals at out of band. The maximum insertion loss is 3.5 dB.
Fig.4-7. Receiver part PCB Layout
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
19
4.2.4 Transmit Section
4.2.4.1 An Overview of Transmit Section
Fig.4-8. Transmitter block diagram
The transmit (TX) section consists of an I/Q baseband upconverter, an offset phase-locked loop
(OPLL) and two 50 ohms output buffers that can drive external power amplifiers (PA), one for the
EGSM 900 (880 – 915 MHz) bands and one for the DCS 1800 (1710 – 1785 MHz) bands. The OPLL
requires no external duplexer to attenuate transmitter noise and spurious signals in the receive
band, saving both cost and power. Additionally, the output of the transmit VCO (TXVCO) is a
constant-envelope signal which reduces the problem of spectral spreading caused by nonlinearity in
the PA.
A quadrature mixer upconverts the differential in-phase (TXIP,TXIN) and quadrature(TXQP,TXQN)
signals with the IFLO to generate a SSB IF signal which is fitered and usesd as the reference input
to the OPLL. The Si4133T generates the IFLO frequency between 766 and 896 MHz. The IFLO is
divided by two to generate the quadrature LO signals for the quadrature modulator, resulting in an IF
between 383 and 448 MHz.
The OPLL consists of a feedback mixer, a phase detector, a loop filter, and a fully integrated
TXVCO. The TXVCO is centered between the DCS 1800 and PCS 1900 bands, and its output is
divided by two for the generate the RFLO frequency between 1272 and 1483 MHz. To allow a single
VCO to be used for the RFLO, high-side injection is used for the EGSM 900 bands, and low-side
injection is used for the DCS 1800 and PCS 1900 bands. The I and Q signals are automatically
swapped within the Si4200 when switching bands.
Low-pass fitlers before the OPLL phase detector reduce the harmonic content of the quadrature modulator
and feedback mixer outputs. The cutoff frequency of the filters is programmable.
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
20
4.2.4.2 Transmitter Part
A. 3 dB attenuator : Z705, Z706
B. ASM(Antenna Switch Module / built in LPF): Z701
This filters only the signals within frequency band of 880~915MHz, 1710MHz~1785MHz which is
the transmit frequency of GSM, DCS system terminal, and it eliminates other images and spurious
components than the terminal transmit frequency.
C. Power AMP Module: U701
This device amplifies signals before transmiting them through the antenna in sufficient strength
from the terminal to the base station. It has amplification factor of 28dB and efficiency of about 53%
typically in GSM band and amplification of 27dB and efficiency of about 53% typically DCS band.
D. Antenna: ANT J702
This device enables signals to be transmitted and received from BTS by Um interface.
Fig.4-9. Transmit part PCB Layout
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
21
4.2.5 Offset PLL
4.2.5.1 An Overview of Offset PLL
Fig.4-10. Si4133T Frequency Synthesizer Block Diagram
The Si4133T dual frequency systhesizer is a monolithic CMOS integrated circuit that performs IF
and RF synthesis. Two complete PLLs are integrated including VCOs, varactors, resonators, loop
filters, reference and VCO dividers, and phase detectors. Differential outputs for the IF and RF
PLLs are provided for direct connection to the Si4200 transceiver IC. The RF PLL uses two
multiplexed VCOs. The RF1 VCO is used for Receive mode, and RF2 VCO is used for Transmit
mode. The IF PLL is used only during Transmit mode and uses a single VCO.
The frequency synthesizer uses VC-TCXO(13MHz) as reference frequency. 13MHz of VC-TCXO is
sent to the frequency synthesizer as a reference input.
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
22
4.2.5.2 VC-TCXO(Voltage Controlled Temperature Compensated Crystal Oscillator): V801
This is the mobile station system reference frequency source. Its frequency is 13MHz, this signal is
applied to Si4133T(U601)_pin7, Si4201(U702)_ pin7 and AD6522(U101).
Fig.4-11. Top view of VCTCXO part on the PCB artwork
Fig.4-12. VCTCXO schematic circuit
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
23
Model No.
Description
Maker
Remark
8960
GSM Mobile Station
Test Set
Agilent Technologies
8593E
Spectrum Analyzer
Hewlett Packard
TDS 340A
Oscilloscope
Tektronix
FLUKE 87
Digital Multimeter
Fluke
E3630A
DC Power Supply
Hewlett Packard
Others
Accessory
Interface Connectors
RF Connectors
RS-232C
PHONE
Coupler
8960 Test Set
8593E Spectrum Analyzer
Power Supply
Section 5. Alignment Procedure
5.1 Recommended Test Equipment
5.2 Connection of Test Equipment
Fig.5-1. Test Set Configuration
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
24
CP100
Terminal
CP100
SECTION 6. Equipment Repair Procedure
6.1 No Power On with battery Applied.
6.1.1 Power CHECK
1.Check battery power : 3.5V~4.2V.
BATTERY PACK
2.Check to see if U104.23 pin voltage is same with battery power : CP100
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
25
CP101
CP101
3. Check to see if Q114.7.8 and 9 pin is same with battery power : CP101
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
26
CP103
CP102
CP102
CP107
4. Check to see if U106 .1 pin is same with battery power : CP102
5. Check to see if U104. 22,21.24 and 6 pin is 2.45V, 2.75V, 2.5V : CP103
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
27
CP103
CP104
CP104
CP105
6. Check to see if U104.2 pin becomes to 0V : CP104
Pressing “END” key to turn on equipment.
7. Check to see if C115,C116,C117,C118,C119 and C120pin is 2.45V : CP105
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
28
CP106
CP106
CP105
8. Check to see if U105.39,12 pin , U117.5pin and U122.5 pin is 2.75V : CP106
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
29
CP107
CP107
CP108
9. Check to see if U106.5 pin and U108.7.32 pin is 2.8V : CP107
6.1.2 Oscillation CHECK
1. Check to see if U101 No. A3 and B3 pin is oscillated(32.768KHz) : CP108
NO Check R128 and then replace X101
3
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
30
CP114
CP108
CP109
CP109
2. Check to see if U107.4 pin Master Clock(13MHz). : CP109
NO Check U107 No. 1.2 pin and then check the PCB pattern, soldering
6.1.3 KEYPAD LED Not in Operation( blue )
1.Check to see if R127. 1 pin is around 2.75V(duty:80%, 256Hz) : CP110
NO Check R127 and Q106 and then replace those
2.Check to see if R123.124.125.126.141.142 is same with battery voltage : CP111
NO Check the PCB pattern between battery and the resistors.
NO Replace the resistors.
3.Check to see if D108.109.110.111.112.113.114.115.116.117.118.120 is well operated by multimeter :
CP112
NO Replace the LEDS.
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
31
CP111
CP112
CP110
CP110
CP112
CP111
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
32
CP113
.1.4 LCD Backlight Not in Operation(White)
1. Check to see if J103.4 pin or 17pin is around 2.75V : CP113
2. NO Check J103 and resoldering
6.1.5 Power indicated LED & Status LED
During Stand By Mode
Status D301should be flashing during Stand By(Blue).
1.Check to see if J103.2pin voltage is around 2.75V : CP114
2.Check to see if Q2 is well operated : CP116 NO Replace the Transistors.
3.Check D301 with multimeter : CP117 NO Replace the LED.
During Incoming Call Mode.
Status D301 should be blinking during Incoming Call (all colors: Green, Red, Blue ).
1. Check to see if J103.2,3,29 pin voltage is around 2.75V : CP114, CP115
2.Check to see if Q1.Q2 is well operated. : CP116
NO Replace the Transistors.
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
33
CP114
CP115
CP114
CP115
CP116
CP117
3.Check D301 with Multimeter : CP117
NO Replace the LED.
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
34
6.2 Audio Part ( Earpiece, Hands-free Earphone, Microphone, Hands-free Mic )
6.2.1 No receiving tone heard( Ear-piece )
1.Check to see if U102 Nos. F10.A9 and J8(C118.C119.C120) is 2.45V_A : CP118
2.Check to see if U102 No. A7(C126) is around 1.2V : CP119
Set to HP8922M to connect a call and then set to 1Khz.
3.Check U102 No. K8 and K7(C175,C177)pins(Ear Signal) for wave form : CP120
NO Replace U102.
4.Check Earpiece No. EAR+ and EAR-(J304) pin for wave form : CP121
NO Replace Earpiece.
5.Check TP4 for Data form : CP122
6.2.2 No Receivng tone heard ( Hands-free Earphone )
1.Check to see if U102 Nos. F10.A9 and J8(C118. C119. C120) is 2.45V_A: CP118
2.Check to see if 102 No. A7(C126) is around 1.2V : CP119
3.Check to see if U101 No. B11(V156) is around 0V: CP123 NO Check to see J107 : CP124 Set to HP8922M to connect a call and then set to 1Khz.
4.Check C139 No. 1pin for wave form : CP125
5.Check Hands-free Earphone
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
35
CP118
CP120
CP119
CP122
CP125
CP121
3
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
36
CP124
CP123
CP120
CP119
CP122
CP123
CP125
CP118
CP124
3
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
37
CP127
CP129
CP126
6.2.3 Side Tone Not transmitted ( Ear-piece )
Repeat 6-2-1 No receiving tone heard.( Ear-piece )
1.Check to see if Mic + pin is around 1.8V : CP126 NO Check that R103,C183 and R106 is cold solder,broken,short to the other
PCB pattern or not
If you find out any defective part, you replace it.
Set to HP8922M to connect a call and then set to 1Khz with Echo audio mode.
2.Check U102 No. J10(C137) pins for wave form : CP127
NO Replace MIC
3.Check TP2pin for Data form : CP128
6.2.4 Side Tone Not transmitted ( Hands-free Mic. )
Repeat 6-2-2 No receiving tone heard.( Hands-free Earphone ).
1. Check to see if U102 No. H10(C135) pin is 2.5V : CP129
NO Check that R188,R187,C187 and C141 is cold solder,broken,short to the other
PCB pattern or not.
If you find out any defective part, you replace it
Set to HP8922M to connect a call and then set to 1Khz with Echo audio mode.
3.Check U102 No. H10(C135) pins for wave form : CP129 NO Replace Handsfree Mic.
4.Check TP2pin for Data form : CP128
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
38
CP128
CP129
CP128
CP127
CP126
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
39
CP130
CP131
CP132
CP133
CP130
CP131
CP132
CP133
6.2.5 Hook Switch not working
1.Check to see if U110 No.5 is 2.5V : CP130
2.Check to see if U110 No.1 is 0V during pressing Hook Switch : CP131
3.Check to see if U110 No.3 is around 0.3V : CP132
NO Check that R190 and R189 cold solder,broken,short to the other
PCB pattern or not
If you find out any defect, you replace it
4.Check to see if U110 No.4 is around 0V When you press Hook Switch : CP133
NO Check that U110 or R191 cold solder,broken,short to the other
PCB pattern or not
If you find out any defect, you replace it
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
40
CP134
CP135
CP136
CP137
CP135
CP137
CP136
CP134
6.2.6 Melody not ringing
1.Check to see if U108 Nos. 32, 7 is 2.8V : CP134
2.Check to see if U108 Nos. 15 is Vbat : CP135
3.Check U108 Nos. 12, 13, and 14pin for wave form : CP136
NO Check that C173, R140, C174, R143 and R169 cold solder,broken,short to the other
PCB pattern or not
If you find out any defect, you replace it
4.Check SPK No. SPOUT1 and SPOUT2 for wave form : CP137
NO Replacd SPK
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
41
CP138
CP139
CP138
CP139
6.2.7 Vibrator not working
1. Check to see if U101 No. C5(Q105.1) pin is 2.75V(duty:70%, 70Hz) : CP138
NO Check to see Q105 cold solder,broken,short to the other PCB pattern or not
If you find out any defect, you replace it
2. Check to see J105 No. 1 is same with battery power : CP139
NO Check to see J105 and R162 cold solder,broken,short to the other PCB pattern or not
If you find out any defect, you replace it
3.Check to see Vibrator
If you find out any defect, you replace it
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
42
CP140
CP142
CP141
CP140
CP142
CP141
6.3 SIM card part
6.3.1 SIM error
1. Check to see if J104 No. 1 pin is 2.85V : CP140
NO Check to see U104.19 pin cold solder,broken,short to the other PCB pattern or not :
CP141
If you find out any defect, you replace it
2.Check to see J104 Nos.2.3.6 for wave form : CP142
NO Check to see J105,R147 and C145 cold solder,broken,short to the other PCB pattern
or not
If you find out any defect, you replace it
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
43
CP145
CP143
CP144
CP146
6.4 Charger part
6.4.1 Charging error
Insert adaptor into I/O jack.
1. Check to see if U104 No. 10 pin is 5.2V : CP143
NO Check to see J102.23 .24 pin V102 and D121 cold solder,broken,short to the other
PCB pattern or not : CP144
If you find out any defect, you replace it
2.Check to see U104 No.16 pin is low(0V) : CP145
NO Check to see U104 cold solder,broken,short to the other PCB pattern or not
If you find out any defect, you replace it
3.Check to see Q114 No.4 pin is 4.2V : CP146
NO Check to see Q114.R115.C154 cold solder,broken,short to the other PCB pattern
or not
If you find out any defect, you replace it
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
44
CP144
CP146
CP143
CP145
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
45
6.5 RF Part
6.5.1 Test conditions
1. Test condition 1 : VBAT = 3.8V during all tests
2. Test condition 2 : GSM Band
Tx mode
Ch62
Power Level : 13
3. Test condition 3 : DCS Band
Tx mode
Ch698
Power Level : 10
4. Test condition 4 : GSM Band
Rx mode
Ch62
Input power : -70dBm
5. Test condition 5 : DCS Band
Rx mode
Ch698
Input power : -70dBm
6. RF power values are measured using 50Ω coaxial cable.
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
46
Step
Test
point
Typical Value
Condition
Checking Point
2-1
U907
Pin#1
3.8V
2, 3, 4, 5
Check route connection : VBAT
2-2
U907
Pin#5
2.8V
2, 3, 4, 5
Check route connection : VBAT
2-3
TP28
Active Low
2, 3, 4, 5
Check this TP28 with Digital
Oscilloscope. when CALL ACTIVE state
this TP28 Value must be Low.
2-4
U701
Pin#4
3.8V
2, 3, 4, 5
Check route connection : VBAT
2-5
U701
Pin#5
2.8V
2, 3, 4, 5
Check route connection : VCC_RFCHIP
Typ. 2.8V
Typ. 2.8V
6.5.2 Power Supply Check Point
Fig.6-1 U907 Regulator Power Supply PCB Layout
Fig.6-2 U907 Regulator Power Supply Schematic
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
47
TP 28
Fig.6-3 TP28 location in the circuit
Fig.6-4 TP28 on the PCB Layout
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
48
Typ. 2.8V
Typ. 3.8V
Fig.6-5 U701 PAM’s Power Check Point
Fig.6-6 U701 PAM’s PCB Layout
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
49
Step
Test
point
Typical Value
Condition
Checking Point
3-1
U701
Pin#3
Logic High
2, 3
Check route connection : TXEN
3-2
U701
Pin#2
Logic High
3, 5
Check this pin 2, When Logic High,
then DCS Mode. While Logic Low ,
GSM mode is operating.
Logic Low
2, 4
STEP 3-1
6.5.3 Power Amplifier Module
- First check the Power Supply Check point following 6.3.2. Then you can trace the guideline of PAM as
follow .
Fig.6-7. PAM TXEN Test Point Circuit
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
50
STEP 3-2
STEP 3-2
Fig.6-8. PAM DCSSEL Test Point Circuit
Fig.6-9. PAM TXEN and DCSSEL Test Point on the PCB Layout
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
51
Ste
p
Test point
Typical Value
Condition
Reaction to Abnormality
4-1
V801
Pin#1
0.5V ~ 2.5V
2, 3, 4, 5
Check route connection : AFC
4-2
V801
Pin#4
2.7V
2, 3, 4, 5
Check R801
Check route connection : VTCXO
4-3
CP 1
Refer to Fig6-12
2, 3, 4, 5
Check and if short to GND then
Replace V801 with new one
4-4
CP 2
Refer to Fig6-12
2, 3, 4, 5
Check connection L801, C803, R803, R805,
R808, C806, C804
Replace Q801
STEP 4-3
STEP 4-4
6.5.4 VCTCXO
Fig.6-10. VCTCXO Check Point Circuit
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
52
STEP 4-4
STEP 4-4
Fig.6-11. VCTCXO Check Point on the PCB Layout
Fig. 6-12 VCTCXO Outputs
PANTECH R&D CONFIDENTIAL
CUTE-FRIME Service Manual
53
Step
Test point
Typical Value
Condition
Check point
5-1
Z701
Pin#11
2.6V
2
When Pin#11 is Logic High and Pin#2
is Logic Low the mode is EGSM band.
While Pin#2 is Logic High and Pin#11
is Logic Low the operating mode is
DCS band.
5-2
Z701
Pin#2
2.6V
3
STEP 5-2
STEP 5-1
6.5.5 Antenna Switch Module
Fig. 6-13 Antenna Switch Module Circuit
Fig. 6-14 Antenna Switch Module PCB Layout
PANTECH R&D CONFIDENTIAL
Loading...