The difference between POE fiber optic transceiver and ordinary fiber optic transceiver

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.