File name Samsung SGH-i750 service manual.pdfGSM TELEPHONE
SGH-i750
GSM TELEPHONE
1. 2. 3. 4. 5. 6. 7. 8.
CONTENTS
Specification Circuit Description Exploded Views and Parts List Electrical Parts List Block Diagrams PCB Diagrams Flow Chart of Troubleshooting Disassembly and Assembly instructions
1. Specification
1-1. GSM General Specification
GSM900 Phas e 1 Fr eq. Band[MHz] Uplink/ Downli nk ARFCN r ange 890~915 935~960 1~124 EGSM 900 Phas e 2 880~915 925~960 0~124 & 975~1023 45MHz 270.833kbps 3.692us 576.9us 4.615ms 0.3GMSK 33dBm~5dBm 5pcl ~ 19pcl -102dBm 8 35Km DCS1800 Phas e 1 1710~1785 1805~1880 512~885 PCS1900 1850~1910 1930~1990 512~810 80MHz 270.833kbps 3.692us 576.9us 4.615ms 0.3GMSK 30dBm~0dBm 0pcl ~ 15pcl - 100dBm 8 -
Tx/ Rx s paci ng Mod. Bit r ate / Bit Pe r iod T ime Slot Period / F rame Peri od Modulati on MS Power Power Cl a ss Sensit ivit y TDMA Mux Cell Radius
45MHz 270.833kbps 3.692us 576.9us 4.615ms 0.3GMSK 33dBm~5dBm 5pcl ~ 19pcl - 102dBm 8 35Km
95MHz 270.833kbps 3.692us 576.9us 4.615ms 0.3GMSK 30dBm~0dBm 0pcl ~ 15pcl - 100dBm 8 2Km
1-1
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Specification
1-2. GSM TX power class
TX Power control level
5
GSM900
TX Power control level
0
DCS1800
TX Power control level
0
PCS1900
33±3 dBm
30±3 dBm
30±3 dBm
6
31±3 dBm
1
28±3 dBm
1
28±3 dBm
7
29±3 dBm
2
26±3 dBm
2
26±3 dBm
8
27±3 dBm
3
24±3 dBm
3
24±3 dBm
9
25±3 dBm
4
22±3 dBm
4
22±3 dBm
10
23±3 dBm
5
20±3 dBm
5
20±3 dBm
11
21±3 dBm
6
18±3 dBm
6
18±3 dBm
12
19±3 dBm
7
16±3 dBm
7
16±3 dBm
13
17±3 dBm
8
14±3 dBm
8
14±3 dBm
14
15±3 dBm
9
12±4 dBm
9
12±4 dBm
15
13±3 dBm
10
10±4 dBm
10
10±4 dBm
16
11±5 dBm
11
8±4dBm
11
8±4dBm
17
9±5 dBm
12
6±4 dBm
12
6±4 dBm
18
7±5 dBm
13
4±4 dBm
13
4±4 dBm
19
5±5 dBm
14
2±5 dBm
14
2±5 dBm
15 1-2
0±5 dBm
15
0±5 dBm
SAMSUNG Proprietary-Contents may change without notice
This Document can not be used without Samsung's authorization
2. Circuit Description
2-1. SGH-i750 RF Circuit Description
2-1-1. ANTENNA SWITCH (U101:LMG003S-5091A)
Switching Tx, Rx path for EGSM900, DCS1800 and PCS1900 by logic controlling. < Truth Table >
VC1 Tx Mode (GSM900) Tx Mode (DCS1800/1900) Rx Mode (GSM900) Rx Mode (DCS1800) Rx Mode (PCS1900) L L L L H VC2 H L L L L VC3 L H L L L
2-1-2. FILTER
To convert Electromagnetic Field Wave to Acoustic Wave and then pass the specific frequency band. - GSM FILTER (F101) For filtering the frequency band between 925 and 960 MHz - DCS FILTER (F103) For filtering the frequency band between 1805 and 1880 MHz. - PCS FILTER (F102) For filtering the frequency band between 1930 and 1990 MHz.
2-1-3. TRANSCEIVER (U102:UAA3587EHN/C2)
This chip is fully integrated GSM GPRS quad-band transceiver with transmit baluns, loop filters and most of the passive component in it. And also fully integrated fractional N RF synthesizer with AFC control possibility, RF VCO with integrated s |