1、Specification requirements:
A. It has 3-way 10 / 100bast-t (x) adaptive network ports;
B. It has its own network isolation transformer with 2.00mm double row pins;
C. Power input: dc3.3v/1a, input from power pin;
D. Power consumption: full load power consumption is not more than 2W;
E. Forwarding mechanism: store and forward mechanism, line speed performance;
F. It has the function of MDI / mdix;
G. Working temperature: - 40 ~ 75 ℃;
H. Management attribute: non network management type
2、Scheme selection:
5-port 100 MB switching chip, 3 network ports, lead out in pin mode;
3、Module production process:
A. 4-layer PCB, FR-4 high Tg board, 1.6 mm thick;
B. The pad is deposited with gold and the via is covered with green oil;
C. The power supply and network data interface are connected with the base plate by gold-plated pins;
4、Pin definition:
Power pin: as shown in the figure:

Among them: 1, 2, 3 and 4 are power supply ground, 5, 6, 7 and 8 are 3.3V power supply 3-way network port pin: as shown in the figure:

21. The twisted pair signal P1 at the first road network port_ TX0+
22. The twisted pair signal P1 at the first road network port_ TX0-
17. The received signal P1 of twisted pair at the first road network port_ RX1+
18. The received signal P1 of twisted pair at the first road network port_ RX1-
13. The signal P2 of the twisted pair at the second road network port_ TX0+
14. The signal P2 of the twisted pair at the second road network port_ TX0-
9. Receiving signal P2 of twisted pair at road network port 2_ RX1+
10. Receiving signal P2 of twisted pair at road network port 2_ RX1-
5. The signal P3 of the twisted pair at the third road network port_ TX0+
6. The signal P3 of the twisted pair at the third road network port_ TX0-
1. Receiving signal P3 of twisted pair at the third road network port_ RX1+
2. Receiving signal P3 of twisted pair at the third road network port_ RX1-