POE interface protection Series (1) - PD protection
1. Abstract
POE, the short for Power Over Ethernet, according to the composition of the system, mainly divided into PD and PSE two parts, of which, PD is the power device, the load side, common such as IPC, AP, etc.;PSE is power supply equipment, such as POE switches.
2.PD interface protection
POE interface equal to Ethernet port + power supply interface, and PD interface is decomposed into Ethernet port + power supply interface. In ITU standard, there are corresponding test requirements for decomposing Ethernet ports and power supply interfaces. As follows:
The standard test method is not described here. Please leave a message if you need it. According to the test requirements, for the external Ethernet port, the maximum energy is the common mode 6kV 7Ω test requirements, the current is about 850A, the energy is relatively large, need to be shared by multiple components; According to the requirements of the standard, the insulation impedance of DC500V greater than 2MΩ must be met after the test.
In summary, we recommend the following solutions for PD interface:
3.Summary
■Some customers do not care about the withstand voltage requirements of DC500V, often directly omit the GDT(to the earth), use TVS directly to the chassis Gnd, can be adjusted according to the actual application needs;
■ The rectifier bridge of PD needs to meet more than 850/2A of 8/20μs current impact in the test stress.Through the actual test, the 1A above Schottky can meet the test stress, and the withstand voltage is recommended to be greater than 100V.
■ If the next PD IC is domestic IC, relatively fragile, need to increase some special protection, there is a need to contact us, we can do the relevant rectification;
