Research of Power-On Detection in POE Topology
Zhao Han, Jie Wu, Qing Yun Dong, Ke Ren, Juan Dong · Advanced materials research · 2014
POE (Power Over Ethernet) realizes the multiplexing of power transmission and data transmission. To ensure the safety of power supply process, PD (Powered Device), when connected, must be detected by PSE (Power Sourcing Equipment). This article describes the methods of PD detection especially in the symmetrical architecture. The symmetrical architecture means that PSE and PD are connected and either of them can play a role of PSE or PD. In our new approach, signature resistance is replaced by signature capacitance. The connection of PD changes the capacitance load of the system, so the step response can be used to detect the change of capacitance load. This method requires zero static current, which reduces the system power consumption. The theoretical analysis, PSPICE simulation and the experimental results are given.