Samsung SCH-2500 Service Manual
PORTABLE CELLULAR
TELEPHONE
SCH-2500 Series
Manual
SERVICE
PORTABLE CELLULAR TELEPHONE CONTENTS
1. General Introduction
2. Specification
3. Installation
4. Nam Programming
5. Circuit Description
6. Trouble shooting
7. Exploded Views and its Parts List
8. Electrical Parts List
9. PCB Diagrams
10. Block Diagrams
11. Circuit Diagram
SAMSUNG Proprietary - Contents may change without notice
Samsung Electronics Co.,Ltd.
GH68-00621A
1999. 9. Rev. 1.0
1. General Introduction
The SCH-25XX DBTM phone functions as analog phone working in AMPS (Advanced Mobile Phone Service)
mode, digital cellular phone working in CDMA (Code Division Multiple Access) mode, and digital phone
working in PCS (Personal Communication Service) mode.
The following standards and minimum performance standards shall be met or exceeded by each subscriber
unit.
Air Interface
The Subscriber Unit shall be Triple mode and Dual band in compliance with ANSI J-STD-008 and TIA/EIA IS98A.
MS(Mobile Station) meets the specifications of the below;
ANSl J-STD-008 : Personal Station-base Station Compatibility Requirements for 1.8 to 2.0 GHz CDMA
PCS.
ANSl J-STD-018 : Recommended Minimum Performance Requirements for 1.8 to 2.0 GHz CDMA Personal
Stations.
CDG Ref. Document #27 : High Rate Speech Service Option for Wideband Spread Spectrum Systems.
TlA/ElA lS-95A : Mobile Station-Base Station Compatibility Standard for Dual-Mode Wideband Spread
Spectrum Cellular System.
IS-96A : Speech Service Option 1 Standard for Dual-Mode Wideband Spread-Spectrum Cellular Syatems.
IS-98A : Standard for Dual-Mode Wideband Spread Spectrum Cellular Mobile Station.
IS-126 : Mobile Station Loopback Service Options Standard.
SCH-25XX is composed of main handset, rapid charger, cradle, two batteries (1000 mAh, 1600 mAh), handfree kit, and travel charger. Hands-free Kit is designed to be operated in full-duplex mode taking turn-around
delay between the phone and the system into account.
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General Introduction
Memo
2. SPECIFICATION
2-1. General
ITEM PCS CDMA AMPS
Tx Freq. range 1850 ~ 1910MHz 824 ~ 849MHz 824~849MHz
Rx Freq. range 1930 ~1990MHz 869 ~894MHz 869 ~894MHz
Channel Bandwidth 1.23 MHz 1.23 MHz 30 KHz
Channel Spacing 50 KHz 30 KHz 30 KHz
Number of Channel 1200 20FA 832
Duplex Separation 80 MHz 45 MHz 45 MHz
Type of Emission 1M25F9W 40K0F8W,40K0F1D 40K0F8W,40K0F1D
In/Output Impedance 50Ω 50Ω 50Ω
Tx Intermediate Freq. 130.38MHz 130.38MHz 130.38MHz
Rx Intermediate Freq. 210.38MHz 85.38MHz 85.38MHz
Tx Local Freq. lst(FTX-130.38MHz) lst(FTX+130.38MHz) lst(FTX+130.38MHz)
2nd(260.76MHz) 2nd(260.76MHz) 2nd(260.76MHz)
Rx Local Freq lst(FRX-210.38MHz) lst(FRX+85.38MHz) lst(FRX+85.38MHz)
2nd(420.76MHz) 2nd(170.76MHz) 2nd(170.76MHz)
TCXO freq 19.68MHz 19.68MHz 19.68MHz
Freq. Stability (FRX-80MHz)±150Hz (FRX-45MHz)±300Hz ±2.5ppm
Operating Temperature -30
o
C
~ +60
o
C
-30
o
C
~ +60
o
C
-30
o
C
~ +60
o
C
Supply Voltage +3.6V
Size and Weight STD : 122cm X 50cm X 26cm, 161 g, 1000 mA
MID : 122cm X 50cm X 30cm, 179 g, 1600 mA
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2-2. 1.9GHz CDMA(US PCS)
1) General
Frequency Range
.Transmitter : 1850-1910MHz
.Receiver : 1930-1990MHz
Channel Bandwidth : 1.23MHz
Channel Spacing : 50kHz
Number of Channels : 1200
Duplex Seperation : 80MHz
Type of Emission : 1M25F9W
Input/Output impedance : 50 Ω
Intermediate Frequency
.Transmitter : 130.38MHz
.Receiver : 210.38MHz
Local Frequency
.Transmitter : lst(FTX-130.38), 2nd(260.76MHz),
.Receiver : lst(FRX-210.38MHz), 2nd(420.76MHz),
TCXO Frequency : 19.68MHz
Frequlency Stability : (FTX-80MHz)±150Hz
Operation Temperature : -30
o
C
~ 60
o
C
Supply Voltage : +3.6V
2) Transmitter
Waveform Quality : 0.944 or more
Open Loop Power Conterol Range
. -25dBm : -60.5dBm ~ -41.5dBm
. -65dBm : -20.5dBm ~ +1.5dBm
. -104dBm : +15.0dBm ~ +30dBm
Minimum Tx Power control : below -50dBm
Closed Loop Power Control Range : ±24dB
Maximum RF Output Power : 200mW(+23dBm)
Occupied Bandwidth : 1.23MHz
Conducted Spurious Emission @ 1.25MHz : -42dBc/30kHz
Specification
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Specification
3) Receiver
Rx Sensitivity and Dynamic Range : -104dBm, FER=0.5% or less
: -25dBm, FER=0.5% or less
Conducted Spurious Emission
. 1930 ~ 1990MHz : <-81dBm
. 1850 ~ 1910MHz : <-61dBm
. All Other Frequencies : <-47dBm
Single Tone Desensitization : lower than 1%
Rx power = -101dBm
Tone power = -30dBm
Tone offset from carrier = ±1.25MHz
Intermodulation Spurious Response Attenuation : lower than 1%
Rx power = -101dBm
Tone 1 power = -43dBm
Tone 2 power = -43dBm
Tone 1 : offset from carrier = ± 1.25MHz
Tone 2 : offset from carrier = ± 2.05MHz
Specification
2-3 800MHz CDMA
1) General
Frequency Range
.Transmitter : 824 ~849MHz
.Receiver : 869 ~894MHz
Channel Bandwidth : 1.23MHz
Channel Spacing : 30kHz
Number of Channels : 20FA
Duplex Seperation : 45 MHz
Type of Emission : 40KOF8W, 40KOF1D
Input/Output Impedance : 50Ω
Intermediate Frequency
.Transmitter : 130.38MHz
.Receiver : 85.38MHz
Local Frequency
.Transmitter : lst(FTX-130.38MHz),2nd(260.76MHz)
.Receiver : lst(FTX-85.38MHz),2nd(170.76MHz)
TCXO Frequency : 19.68MHz
Frequency Stability : (FTX-45MHz)±300Hz
Operation Temperature : -30
o
C
~ 60
o
C
Supply Voltage : +3.6V
2) Transmitter
Waveform Quality : 0.944 or more
Open Loop power Control Range
. -25dBm : -57.5dBm ~ -38.5dBm
. -65dBm : -17.5dBm ~ +1.5dBm
. -104dBm : +18.0dBm ~ +30dBm
Minimum Tx Power Control : below -50dBm
Closed Loop Power Control Range : ±24dB
Maximum RF Output Power : 200mW(+23dBm)
Occupied Bandwidth : 1.23MHz
Conducted Spurious Emission @900 KHz : -42dBc/30kHz
@1.25MHz : -54dBc/30kHz
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Specification
3) Receiver
Rx Sensitivity and Dynamic Range : -104dBm, FER=0.5% or less
: -25dBm, FER=0.5% or less
Conducted Spurious Emission
.869 ~ 894 MHz : <-81dBm
.824 ~ 849 MHz : <-61dBm
.A11 Other Frequencies : <-47dBm
Single Tone Desenstization :lower than 1%
Rx power level = -101dBm
Tone power level = -30dBm
Tone offset from carrier = ± 900kHz
Intermodulation Spurious Response Attenuation : lower than 1%
Rx power = -101dBm
Tone 1 power = -43dBm
Tone 2 power = -43dBm
Tone 1 offset from carrier = ± 900kHz
Tone 2 offset from carrier = ± 1,700kHz
2-5
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Specification
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2-4 800MHZ CELLULAR(AMPS)
1) General
Frequency Range
.Transmitter : 824 ~ 849MHz
.Receiver : 869 ~ 894MHz
Channel Spacing : 30kHz
Number of Channels : 832
Duplex Seperation : 45MHz
Frequency Stability : ±2.5ppm(-30
o
C
~ 60
o
C
, -22°F ~ 140°F)
Modulation/Demodulation
.Voice : PM
.Data : FM
Operating Temperature : -30
o
C
~ 60
o
C
, -22°F ~ 140°F
Supply Voltate : +3.6V
2) Transmitter
RF output power : 0.6W(+2/-4dB)
Carrier ON/OFF conditions
“ON” Condition : within ±3dB of specification output (in 2 ms)
“OFF” Condition : below -60dBm (in 2 ms)
Compresssor
Compression Rate : 2 : 1
Attack Time : 3ms
Recovery Time : 13.5ms
Reference Input : input power level for producing a nominal ±2.9kHz
: peak frequency deviation of transmitted carrier
Preamphasis : 6dB/oct within 0.3 ~ 3kHz
Maximum Frequency Deviation
F3 of G3 : ±12kHz
Supervisory Audio Tone : ± 2kHz(±10%)
Signling Tone : ± 8kHz(±10%)
Wideband Data : ± 8kHz(±10%)
Post Deviation Limiter Filter
3.0 ~ 5.9 kHz : above 40 LOG(F/3000)dB
5.9 ~6.1 kHz : above 35dB
6.1 ~15 kHz : above 40 LOG(F/3000)dB
Over 15 kHz : above 28 dB
Spectrum Noise Suppression
For all modulation
fo +20 kHz ~ fo +45 kHz : above 26dB
For modulation by voice and SAT
fo +45 kHz : above 63dB+10LOG(PY)dB
For modulation by WBD(without SAT) and ST(with SAT)
fo +45 kHz ~ fo + 60 kHz : above 45 dB
fo +60 kHz ~ fo + 90 kHz : above 65 dB
fo +90 kHz ~ 2 fo : above 63 dB + 10 LOG(PY) dB
(where fo = carrier frequency
PY = mean output power in watts)
Harmonic and conducted Spurious Emissions : below 43 + 10 LOG(PY) dB
3) Receiver
De-emphasis : -6dB/oct within 0.3 ~ 3KHz
Expandor
Expandor Rate : 1 : 2
Attack time : within 3 ms
Recovery Time : Within 13.5 ms
Recovery input : output power level to a 1000Hz tone from
a carrier within ±2.9 kHz peak frequency deviation
Sensitivity : 12 dB SINAD/-116dBm
Intermodulation Spurious Response
Attenuation : above 65dB
RSSI Range : avoce 60dB
Protection Against
Spurious Response Interference : above 60dB
Specification
2-7
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Specification
In Band Conducted Spurious Emission
Transmit Band : below -60dBm
Receive Band : below -80dBm
Out of Band Conducted
Spurious Emissions : below -47dBm
Radiated Spurious Emission
Frequency Range : Maximum Allowable EIRP
25 ~ 70MHz : -45dBm
70 ~ 130MHz : -41dBm
130 ~ 174 MHz : -41 ~ -32dBm
174 ~ 260 MHz : -32dBm
260 ~ 470 MHz : -32 ~-26dBm
470 ~ 1G MHz : -21dBm
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TEx REx xx x
T-xx Dxxx -xx
Pxxx PCHxxxx
xx xx
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Specification
2-5 PCS Debug Display Information
To select debug display mode : prgss [MENU] + [8] and press [0] + [0] +[0] +[0] +[0] +[0] and press [1] or OK
IN CONVERSATION MODE
Sxxxxx : SID (System Identification) toggle
Nxxxxx : NID (Network Identification) toggle
Slx : Slot cycle index (lowest between the system
and the phone will be used)
1. SIO : Slot Index 0
2. SI1 : Slot Index 1
3. SI2 : Slot Index 2
Handset Status
T-xx : Tx adjust, Value ranges from +63 ~ - 63dB
Dxxx : Sector power in dBm
-xx : ec/Io
Pxxx : PN offset
CHxxxx : Channel number
TV : Tx vocoder rate (8 is full rate, 1 is 1/8th rate)
RV : Rx vocoder rate (8 is full rate, 1 is 1/8th rate)
xx : Walsh code used in traffic channel
System acquisition state
SIDxxxxx SIx x
T-xx Dxxx -xx
Pxxx PCHxxxx
xx xx
IN IDLE MODE
0 - NO SVC
1 - Synchronization(Init)
2 - Paging (Idle)
3 - Vocoder-Init
4 - Waiting for order
5 - Waiting for answer
6 - Conversation state
7 - Release
8 - Overhead
9 - Origination
A - Page - Reg
B - Order - Reg
C - Reg
D-Msg
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Specification
2-6 CDMA Debug Display Information (menu 8)
To select debug display mode : prgss [MENU] + [8] and press [0] + [0] +[0] +[0] +[0] +[0] and press [1] or OK
TEx REx xx x
T-xx Dxxx -xx
Pxxx CCHxxxx
IN CONVERSATION MODE
Sxxxxx : SID (System Identification) toggle
Nxxxxx : NID (Network Identification) toggle
Slx : Slot cycle index (lowest between the system and
the phone will be used)
Handset Status
T-xx : Tx adjust, Value ranges from +63 ~ -63dB
Dxxx : Sector power in dBm
-xx : ec/Io
Pxxx : PN offset
CHxxxx : Channel number
TEX : Tx vocoder rate (8 is full rate, 1 is 1/8th rate)
REX : Rx vocoder rate (8 is full rate, 1 is 1/8th rate)
xx : Walsh code used in traffic channel
SIDxxxxx SIx x
T-xx Dxxx -xx
Pxxx CCHxxxx
IN IDLE MODE
0 - NO SVC
1 - Synchronization(Init)
2 - Paging (Idle)
3 - Vocoder-Init
4 - Waiting for order
5 - Waiting for answer
6 - Conversation state
7 - Release
8 - Overhead
9 - Origination
A - Page - Reg
B - Order - Reg
C - Reg
D-Msg
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SIDxxxxx : AMPS Home System ID
PWRx : Power Level 0 ~ 7
SATx : Supervisory Audio Tone code (0 ~ 3)
x (Using Frequency Band) : A Band or B Band
RSSIxxx : RSSI value
CHxxx : Using Channel
Handset Status :
System acguisition state
2-7 AMPS Debug Display Information
To select debug display mode : prss [MENU] + [8] and press [0] + [0] +[0] +[0] +[0] +[0] and press [1] or OK
SIDxxxxx x x
PWRx RSSIxxx
SATx ACHxxxx
xx xx
Specification
1 - Initialization state
2 - Idle state
3 - Vocoder - Init
4 - Waiting for order
5 - Waiting for answer
6 - Conversation
7 - Release
8 - System acguisition
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Specification
Memo
6. Trouble shooting.
6-1. Logic Section
6-1-1 No Power
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