Electrical port module

Abstract

This invention relates to the technical field of optical communication, and specifically relates to an electrical port module. The electrical port module comprises at least one first-stage protection circuit, a network interface socket, a network transformer, a second-grade protection circuit and a network card physical interface chip; the network interface socket, the network transformer, the second-grade protection circuit and the network card physical interface chip are electrically connected in sequence; the network transformer is used for isolating the network interface socket and the network card physical interface chip; the first-stage protection circuit is electrically connected between the center tap of the first end of the network transformer and the ground, and is used for limiting common mode surge signals received from the network interface socket; and the second-grade protection circuit is arranged between the positive end and the negative end of a differential signal line of the second end of the network transformer, and is used for limiting difference mode surge signals received from the network interface socket. The electrical port module is prevented from being damaged by lightning surge signals received from the network interface socket; and thus, the reliability of the whole module is improved.

Description

【Technical field】 [0001] The present invention relates to the technical field of optical communication, in particular to an electrical port module. 【Background technique】 [0002] The optical module is a commonly used photoelectric conversion accessory, which can be interconnected with various photoelectric conversion devices, such as optical fiber transceivers, optical transceivers, etc. Usually, an optical module includes not only an optical transceiver module and corresponding functional circuits, but also some interface modules. For example, the optical module usually includes an optical port module, and the commonly used interface type is an LC interface, which is used to connect the optical fiber jumper or pigtail of the LC head; it also includes an electrical port module, and the commonly used interface type is an RJ45 interface, which is used to realize communication with the LC head. Network cable connection. [0003] Among them, the electrical port module has bee...

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Problems solved by technology

However, the electrical port module uses a network cable as the transmission medium, and in actual use, the network cable is often laid outdoors, which is easily affected by lightning surge signals, and the internal circuit of the optical module itself does not have the ability to prevent lightning strikes, and the lightning surge energy will be damaged. Optical modules or other photoelectric conversion equipment, causing unnecessary economic losses

[0004] The electrical port module in the prior art includes a network card physical interface chip, a network transformer, a network interface socket and a series of impedance matching circuits, and usually only a bob-smith circuit is used for impedance matching between the network transformer and the network interface socket. lightning protection circuit

Moreover, in the prior art, common-mode inductors and transformers are used to suppress common-mode surge protection. However, due to the distributed capacitance of the transformer, the isolation effect of the actual common-mode surge is reduced, and some common-mode surge energy is still coupled to the The secondary end of the network transformer, and then damage the physical interface chip and internal functional modules of the network card

[0005] Moreover, the optical modules currently used need to comply with the SFP MSA protocol, that is, there are requirements on the size of the module, and the layout space is very limited. Therefore, there are strict requirements on the size of the lightning protection circuit in the electrical port module.

Although there are currently some lightning protection chips on the market, which are expensive and have a large package, in order to place such protection devices on the PCB, a specially customized network transformer and network interface socket are needed to save the layout space, but even if using After the above-mentioned customized devices, the PCB layout is still very crowded, which increases the module cost and also affects the module performance. Therefore, this type of protection chip is not suitable for use in electrical port modules, which are small in size and have strict cost requirements.

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