Samsung SCH-A205 service manual, samsung service manuals schematy serwisowki
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DUAL MODE(CDMA/AMPS)
PORTABLE TELEPHONE
SCH-A205
SERVICE
Manual
DUAL MODE TELEPHONE
CONTENTS
1. General Instruction
2. Specification
3. Circuit Description
4. NAM Programming
5. Test Procedure & Test Command
6. Electrical Parts List
7. Block Diagram
8. PCB Diagram
9. Schematic Diagrams
10. Exploded View & Its Part List
ELECTRONICS
Samsung Electronics Co.,Ltd. Dec. 99
Pinted in Korea.
Code No.: GH68-02022A
1. General Instruction
The SCH-A205 cellular phone functions as both analog cellular phone working in AMPS(Advanced
Mobile Phone Service) mode and Digital cellular phone working in CDMA(Code Division Multiple
Access) mode.
CDMA type digital mode applies DSSS(Direct Sequential Spread Spectrum) mode which first came
to be used in the military.
The DSSS reduces channel cross talk and allow to use one frequency channel by multiple users in
the same specific area, resulting in increase of channel capacity to about ten times compared to that
of analog mode currently used.
Soft/Sofer Handoff, Hard Handoff, and Dynamic RF Power Control technologies are combined into
this phone to reduce the call drop while usage.
CDMA digital cellular network consists of MSO(Mobile Switching Office), BSC(Base Station
Controller), BTS (Base Station Transmission System), and MS(Mobile Station). MS meets the specifi-
cations of the below :
¤ IS-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
System
¤ IS-98A : Standards for Dual-Mode Wideband Spread Spectrum Cellular Mobile System
¤ IS-126 : Mobile Station Loopback Service Options Standard
SCH-A205 is composed of main handset, one battery(800mAh), ear-microphone, and rapid DTC.
Travel adaptor(or travel charger) and HFK is optional. Hands-Free Kit is designed to be operated in
full-duplex mode taking turn-around delay between the phone and the system into account.
SAMSUNG Proprietary - Contents may change without notice
1-1
2. Specification
2-1 General
ITEM
CDMA
AMPS
Tx Freq. range
824 ~ 849MHz
824 ~ 849MHz
Rx Freq. range
869 ~ 894MHz
869 ~ 894MHz
Channel Bandwidth
1.23MHz
30KHz
Channel Spacing
30KHz
30KHz
Number of Channel
832
832
Duplex Separation
45MHz
45MHz
Type of Emission
40K0F8W,40K0F1D
40K0F8W,40K0F1D
In/Output Impedance
50ohm
50ohm
Tx Intermediate Freq.
130.38MHz
130.38MHz
Rx Intermediate Freq.
85.38MHz
85.38MHz
Tx Local Freq.
1st(260.76MHz)
2nd(FTX+130.38MHz)
1st(260.76MHz)
2nd(F
TX
+130.38MHz)
Rx Local Freq
1st(FRX+85.38MHz)
2nd(170.76MHz)
1st(F
RX
+85.38MHz)
2nd(170.76MHz)
TCXO freq.
19.68MHz
19.68MHz
Freq. Stability
(F
RX
-45MHz) ±300Hz
±2.5ppm
Operating Temperature
-30°C ~ +60°C
-30°C ~ +60°C
Supply Voltage
3.75V
Size and Weight
STD : 80mm X 43mm X 25.5mm, 85 g, 800 mA
SAMSUNG Proprietary - Contents may change without notice
2-1
2-2 Digital Mode
Waveform Quality
0.944 or more
Time Reference
±1uS or less
Rx Sensitivity and Dynamic Range
-104dBm, FER=0.5% or less
-25dBm, FER=0.5% or less
Maximum TX Output Power
23dBm(200mW)
TX Frequency Deviation
±300Hz or less
Occupied Band Width
1.32MHz
TX Conducted Spurious Emission
900KHz : -42dBc / 30KHz below
1.98MHz: -54dBc / 30KHz below
Minimum TX Power Control
below -50dBm
Open Loop Power Control
-25dBm: -57.0dBm ~ -38.5dBm
-65dBm: -17.5dBm ~ + 1.5dBm
-104dBm: +18.0dBm ~ +30.0dBm
Standby Output Power
below -61dBm
Colsed Loop TX Power Control Range
Test1: ±24dB or less
Test2: 0mS ~ 2.5mS
Test3: ±24dB or more
Test4: ±24dB or more
Test5: ±24dB or more
SAMSUNG Proprietary - Contents may change without notice
2-2
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