Ethernet port circuit

Abstract

The invention discloses an Ethernet port circuit. In the present invention, each pair of differential lines of the Ethernet port circuit is connected to each other through two series diodes with opposite conduction directions, so as to discharge the voltage when the differential mode voltage between each pair of differential lines is too large due to lightning strikes. Discharge energy, so that differential mode protection can be achieved, and because the cost of diodes is much lower than that of transient voltage suppressor diodes (TVS), the cost is reduced while achieving differential mode protection. Further, in order to realize common mode protection, the present invention can also ground the center tap of the transformer on one side of the connector through components that can realize voltage clamping such as varistors, etc. When the common-mode voltage of the common-mode voltage is too large due to lightning strikes, the energy is released, so that common-mode protection can also be achieved.

Description

technical field [0001] The invention relates to port lightning protection technology, in particular to an Ethernet port circuit. Background technique [0002] In the prior art, network devices such as switches usually use integrated Fast Ethernet ports (10 / 100Base-TX) or integrated Gigabit Ethernet ports (1000Base-T), and the Ethernet ports of adjacent network devices will pass through Such as twisted pair and other Ethernet cable connections. [0003] In practical applications, there are many problems in the wiring of Ethernet cables between network devices. Especially when wiring outdoors, Ethernet cables are prone to lightning strikes and generate high-voltage static electricity. If the Ethernet ports are not protected against lightning, it is very easy to Damaged by high-voltage static electricity produces large differential-mode voltage and common-mode voltage, which leads to port failure. [0004] like figure 1 As shown, the existing 100M Ethernet port circuit usual...

AI Technical Summary

Problems solved by technology

[0010] In this way, when the high-voltage static electricity generated by lightning strikes is conducted from the connector to the PHY chip through the transformer, a large common-mode voltage will be generated on each pair of differential lines, but it cannot be released to the ground through the center tap, that is, common-mode protection cannot be achieved

[0011] It can be seen that the cost of differential mode protection for existing Ethernet port circuits is too high, and common mode protection cannot be achieved

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