A low-loss overcurrent protection circuit for Ethernet electrical equipment

Abstract

The invention provides an Ethernet electric equipment overcurrent protection circuit, including four parts, i.e., a threshold circuit, a comparison and amplification circuit, a power supply circuit and a time delay circuit, and aims to prevent damage to equipment from being caused by too large current when Ethernet electric equipment is powered-on or in normal operation. Taking reduction of circuit loss into account, a relatively small protective threshold voltage is selected. In order to reduce error triggering in a threshold voltage switching process, a related time delay circuit is arranged. In order to effectively improve precision of circuit control, the comparison and amplification circuit adopts transistors with relatively small technological deviations as a forward input port and a reverse input port, and a related resistor is introduced to the threshold circuit to reduce errors of a voltage sampling signal and a threshold voltage signal. Therefore, the Ethernet electric equipment low-loss overcurrent protection circuit has the advantages of low loss and high precision while effectively protecting electrification and normal operation of Ethernet equipment.

Description

technical field [0001] The invention relates to the design of an electrical interface circuit for Ethernet equipment, in particular to the design of an overcurrent protection circuit for the electrical interface of equipment. Background technique [0002] When an Ethernet device starts to work with power, an overshoot current will appear to damage the circuit and its components. Moreover, during the normal operation of the equipment, due to the change of the load or the short circuit of the circuit, a large current will also damage the equipment. Therefore, it is necessary to design an overcurrent protection circuit for Ethernet powered equipment to protect the equipment. Since the current rises rapidly in a short period of time during the power-on process of the Ethernet device, the set overcurrent protection threshold should be relatively small. When the equipment is working normally, a relatively large overcurrent protection threshold should be set based on the IEEE802....

AI Technical Summary

Problems solved by technology

[0002] When the Ethernet device starts to work on power, there will be an overshoot current that will damage the circuit and its components

Moreover, during the normal operation of the equipment, due to the change of the load or the short circuit of the circuit, a large current will also damage the equipment.

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