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