The development of Power over Ethernet (POE) technology is very strong. The development of this technology can simplify the installation and deployment of electrical equipment, thus eliminating the need for independent transmission lines. Nowadays, power supply technology (POE) is widely used in industrial systems such as security, communication, and smart grids to achieve data, video transmission, flow control, and power supply through buses within the system. However, due to the harsh working environment of Industrial Ethernet, the surge and static protection of POE port is essential. Here is a brief introduction to the protection scheme of POE system:
Level:
(1) IEC61000-4-2: LEVEL4: Contact 8kV; Air: 15kV
(2) IEC61000-4-5: 10/700us LEVELX: 6KV
Principle: The above two schemes adopt a combination of two-stage protection, with the front stage being an electrostatic silicon suppressor S.E.T and a negative clamp voltage suppressor NVCS, to absorb and release large surge energy. The rear stage protection device is an electrostatic protector ESD, with precise clamp voltage and fast reaction speed, Absorb the residual energy of the previous stage, reduce the voltage to within the range that the back-end circuit can withstand, and protect the back-end chip. In traditional 48V power supply protection, more protective devices are used to improve the testing level, which occupies a large volume and has poor control effect on residual voltage, resulting in an increased probability of back-end chip damage. For this reason, SPSEMI Instant Thunder Electronics has developed a negative clamp voltage suppressor NVCS series material specifically for POE (48V power supply). This material has a large flow rate and a small volume, which is packaged in SMC. In terms of residual voltage control, it is about 20V lower than traditional TVS materials, which can effectively protect the back-end chip.
Level:
(1) IEC61000-4-2: LEVEL4: Contact 8kV; Air: 15kV
(2) IEC61000-4-5: 10/700us LEVELX: 6KV
Principle: The above two schemes adopt a two-stage protection. The front stage is a negative clamp voltage suppressor NVCS, which absorbs and releases large surge energy. The rear stage protection device is an electrostatic protector ESD, which has precise clamping voltage and fast reaction speed. It absorbs the residual energy of the front stage, reduces the voltage to within the range that the back-end circuit can withstand, and protects the back-end chip.
According to the international standard IEC61000-4-5, lightning surge energy is generally injected in a common mode manner. In the design of the scheme, attention is paid to common mode protection. An electrostatic protector TUSD03FB is added between the isolated lines for differential mode protection, eliminating the residual energy coupled to the back end at the moment of lightning strike, and protecting the pressure difference between the lines from changing. The above protection plan has been verified by the SPSEMI Transient Thunder Electronics Laboratory.
The above is a brief overview of POE Power over Ethernet Surge Protection, which can serve as a reference for everyone. Our company has a strong technical team and can provide professional technical services to customers. At present, our company has diversified products: intelligent onu, communication Optical module, optical fiber module, sfp Optical module, olt equipment, Ethernet switch and other network equipment. If you need, you can have a deep understanding.