The difference between POE fiber optic transceiver and ordinary fiber optic transceiver
July 29, 2022
The difference between POE fiber optic transceivers and ordinary fiber optic transceivers is the addition of a POE power supply function. POE refers to a technology that can provide DC power supply for some IP-based terminals while transmitting data signals.
POE power supply process
The process of POE power supply: detection, PD end classification, start of power supply, power supply, power off.
(1) Detection: At the beginning, the POE device outputs a very small voltage at the port until it detects that the connection of the cable terminal is a power receiving device that supports the IEEE802.3af standard.
(2) PD device classification: After detecting the power receiving device PD, the POE device may classify the PD device and evaluate the power loss required by the PD device.
(3) Start of power supply: During a start-up period of a configurable time (generally less than 15μs), the PSE device starts to supply power to the PD device from a low voltage until it provides a 48V DC power supply.
(4) Power supply: Provide stable and reliable 48V direct current for PD equipment.
(5) Power failure: If the PD device is disconnected from the network, the PSE will quickly (usually within 300-400ms) stop the power supply of the PD device, and repeat the detection process to detect whether the terminal of the cable is connected to the PD device .
Optical fiber transceiver PCB board components
The fiber optic transceiver PCB board can be divided into 3 parts and 2 circuits. The 3 parts refer to the power supply part, the network port part, and the optical port part; the 2 circuits refer to the crystal oscillator circuit and the reset circuit.