What is an Ethernet network transformer?

Network transformer is also known as Internet isolation transformer, Ethernet interface transformer and network filter. The products are divided into single port, double port, multi connector, 10 / 100base, 1000Base-TX and RJ45 socket integrated Internet isolation transformer. The products are mainly used in RJ45 network port, Ethernet switch, network router, ADSL, VDSL large digital machine equipment, EOC terminal equipment, EPON / GPON three network integration machine equipment, network set-top box, intelligent TV, network camera, SDH / atmsdh / ATM, PC main board, industrial main board and other machine equipment.

The key functions of network transformer are data signal transmission, impedance matching, wave type repair, low frequency oscillation suppression and high working voltage protection.

The function of network transformer in Ethernet interface is in Ethernet interface machine equipment. When RJ45 is connected according to PHY, a network transformer is added in the middle. Choose network transformer some transformer center tap to receive ground. When connected to the power supply, the value of switching power supply can be different. 3.3V, 2.5V, 1.8V are often available.

Some of the middle taps are connected to the power supply, while some are connected to the grounding device. This key is driven by the application of phy chip UTP port type decision-making. There are two kinds of drive, working voltage drive and current drive. The one driven by working voltage should be connected with power supply; the one driven by electric flow should be connected with a capacitor to the ground immediately. Therefore, for different chips, the wiring method of center tap is closely related to PHY. In fact, we also need to consult the datasheet of chips and design ideas. When the power supply is connected, different working voltage should be connected, which is decided by the level of UTP port number required in the PHY chip material used.