The GX3748 has one user connector, J1. The connector is 62 pin high density D type as shown and described below.

GX3748 J1 Connector
Pin# |
Function |
Pin# |
Function |
Pin# |
Function |
1 |
ID0 |
22 |
ID1 |
43 |
ID2 |
2 |
Channel 0 |
23 |
Channel 16 |
44 |
Channel 32 |
3 |
Channel 1 |
24 |
Channel 17 |
45 |
Channel 33 |
4 |
Channel 2 |
25 |
Channel 18 |
46 |
Channel 34 |
5 |
Channel 3 |
26 |
Channel 19 |
47 |
Channel 35 |
6 |
Channel 4 |
27 |
Channel 20 |
48 |
Channel 36 |
7 |
Channel 5 |
28 |
Channel 21 |
49 |
Channel 37 |
8 |
Channel 6 |
29 |
Channel 22 |
50 |
Channel 38 |
9 |
Channel 7 |
30 |
Channel 23 |
51 |
Channel 39 |
10 |
Channel 8 |
31 |
Channel 24 |
52 |
Channel 40 |
11 |
Channel 9 |
32 |
Channel 25 |
53 |
Channel 41 |
12 |
Channel 10 |
33 |
Channel 26 |
54 |
Channel 42 |
13 |
Channel 11 |
34 |
Channel 27 |
55 |
Channel 43 |
14 |
Channel 12 |
35 |
Channel 28 |
56 |
Channel 44 |
15 |
Channel 13 |
36 |
Channel 29 |
57 |
Channel 45 |
16 |
Channel 14 |
37 |
Channel 30 |
58 |
Channel 46 |
17 |
Channel 15 |
38 |
Channel 31 |
59 |
Channel 47 |
18 |
N/C |
39 |
N/C |
60 |
N/C |
19 |
PUV A |
40 |
PUV C |
61 |
PUV C |
20 |
GND |
41 |
GND |
62 |
GND |
21 |
GND |
42 |
GND |
J1 Pin Out
Legend:
ID0- ID2: Connector ID readback pins.
I/O Channel 0-47 Input channels, 0-15 Group 0, 16-31 Group 1, 32-47 Group 2.
PUV A: Pull up voltage rail for Input channels 0-15.
PUV B: Pull up voltage rail for Input channels 16-31.
PUV C: Pull up voltage rail for Input channels 32-47.
GND: Ground.