1、Module description: LAN8720A is low power consumption of 10 / 100M Ethernet PHY chip, I / O port pin voltage conforms to the standard of IEEE502.3-2005, supported by RMII interface and Ethernet MAC layer communication, built-in 10-BASE-TX full duplex transmission module support 10Mbps and 100Mbps. LAN8720A through negotiation and destination host the best connection (speed and duplex mode), support HPAuto-MDIX automatic flip function no need to replace the cable can be will change the connection is direct or cross connect. 2、Function Description: Can be used as the extension module, Ethernet communication. 3、Description of each function module: ![enter image description here][1] 4、Components and PCB diagram before welding: ![enter image description here][2] 5、Physical map after welding: ![enter image description here][3] ![enter image description here][4] ![enter image description here][5] [1]: /editor/20160418/57146f7c11035.png [2]: /editor/20160418/57146fa735b60.png [3]: /editor/20160503/57284737759d7.JPG [4]: /editor/20160503/5728473a2a345.JPG [5]: /editor/20160503/5728473e0b3d8.JPG