Multitech SocketModem GSM Hardware Manual page 29

Developer Board Schematics
U12F
12
2 SLP
74LCX04
5 RITTL
5 DSRTTL
5 CTSTTL
5
RXDTTL
5 RTSTTL
5 TXDTTL
5 DTRTTL
U3
8
2 DTR
R1IN
9
2 TXD R2IN
11
2 RTS
R3IN
5
2 RXD T1OUT
6
2 CTS
T2OUT
7
2 DSR T3OUT
10
2 DCD
T4OUT
12
2 RI
T5OUT
28
C1+
25
C1-
1
C2+
3
C2-
14
SHDN
13
GND EN
ICL3237E
2 MBAUD
2,4 TIP
2,4 RING
4 TX+
4 TX-
4 RX-
4 RX+
S3-1
S3-4
6 3
5 2
4 1
SW-4PDT SW-4PDT
2 TXCLK
2
RXCLK
Multi-Tech Systems, Inc. SocketModem GSM Hardware Guide for Developers
R194 47K
GND
13
GND
DTRTTL
21
R10UT
20 TXDTTL
R2OUT
RTSTTL
18
R3OUT
24
RXDTTL
T1IN
23
CTSTTL
T2IN
22 DSRTTL
T3IN
19
T4IN
17 RITTL
T5IN
27
V+
4
V-
16
R1OUTB
15
MBAUD
26
VCC
2
GND GND
GND VCC
JP3 P3
1
GND
2
VCC 3
SHUNT
HEADER-3
GND
R195 0
VCC
R196 0
VCC5
S3-3
S3-2
7 10
8 11
9 12
SW-4PDT SW-4PDT
R235 4.7K
VCC
R236 0
C5 .01uF
VCC
GND
U25
1
5
2 RESET VCC VCC
GND
4
3
RESET WDI
ADM6318
R7 0
R8 0
R9 0
JP7
1
3
GND
5
7
9 10
HEADER-5x2
JP13
2
1
HEADER-2
C24 .01uF
VCC
SW3
6 14
U5A
VCC
5
1
4 3
2
3
7
GND
2
74VHC00
1
SW-DPDT
J3 J6
TIP
1
RING
2
3
4
5
6
7
8
9
10
11
10-PIN-SOC
12
12-PIN-SOC
Chapter 5 – The SocketModem Developer Board
C9 .01uF
GND VCC
5
VCC
1
4
U8
2
GND
3
GND
7S32
JP8
1
2
J5
HEADER-2
14
J4
13
12
1
11
2
10 3
GND 4
9
8 5
7 6
CTSTTL
6 7
DSRTTL
5 8
RITTL DCIND
4 9
RXIND
3 10
RXDTTL DTRIND
2 11
TXIND
1 12
14-PIN-SOC 12-PIN-SOC
2
4
6
8
VCC
GND
U5B
4
6
5
VCC
C6 10uF
+
GND
16 V
74VHC00
R57 10K
VCC
1
2
GND
3
4
VCC
R42 200
SPD LED5 RED
5
LED3 RED
COL R41 200
6
LED2 RED
LINK R40 200
7
LED1 RED
ACT R39 200
8
R38 200
FDX LED4 RED
9
10
29
S5
1
3
2 4
GND
SW-SPST
RESET
SPK_N 4
SPK_P 4
MIC_P 4
MIC_N 4
GND
R46 150
LED9 RED
LED8 RED
R45 150
R44 150 LED7 RED
LED6 RED
R43 150
GND
VCC
Place close to
+
the Module.
GND
DCDTTL 5
SPKR 4,5
MIC 5
VCC
LINK 4
ACT 4