Power over Ethernet (PoE)

Image	Part Number	Description / PDF	Quantity	Rfq
	POE-4X18I Laird - Antennas	POE INJECTOR 18W -18V DESKTOP	0
	POE-HP-50I-EU Laird - Antennas	POE INJECTOR 50W 50V DESKTOP	0
	POE-48ID-EU Laird - Antennas	POE INJECTOR 16.8W 48V DESKTOP	0
	POE-24I-CI Laird - Antennas	POE INJECTOR 19.2W 24V DESKTOP	0
	POE-9S-AFI- Laird - Antennas	POE,AFSPLT,9V,12W	0
	POE-9S-AFI Laird - Antennas	POE SPLITTER 9W 9V DESKTOP	0
	POE-24I-L Laird - Antennas	POE INJ 24V 19W	0
	POE-18I-INT Laird - Antennas	POE INJECTOR 16.2W 18V DESKTOP	0
	POE-24S-AFI Laird - Antennas	POE,AFSPLT,24V,12W	0
	POE-48I12S-AFI Laird - Antennas	POE SYSTEM 12VDC 1A AFI	0
	POE-48I5S-AFI Laird - Antennas	POE SYSTEM 5VDC 2.4A AFI	0
	POE-4X48I Laird - Antennas	POE INJECTOR 24W -48V DESKTOP	0
	POE-18I-EU Laird - Antennas	POE INJECTOR 16.2W 18V DESKTOP	0
	POE-48I-CI Laird - Antennas	POE INJECTOR 24W 48V DESKTOP	0
	POE-55IG-AFI Laird - Antennas	POE INJECTOR 30W 55V DESKTOP	0
	POE-48I-EU Laird - Antennas	POE INJECTOR 24W 48V DESKTOP	0

Power over Ethernet (PoE)

1. Overview

Power Supplies (PSUs) provide electrical energy to devices, categorized as external (AC adapters) or internal (mounted within devices). Power over Ethernet (PoE) integrates data and power delivery over Ethernet cables, enabling efficient power management for networked devices. PoE eliminates redundant cabling, reduces installation costs, and supports flexible device deployment in modern applications like IoT, surveillance, and smart buildings.

2. Main Types and Functional Classification

Type	Functional Features	Application Examples
PoE (IEEE 802.3af)	Up to 15.4W, legacy devices	IP phones, basic surveillance cameras
PoE+ (IEEE 802.3at)	Up to 30W, dynamic power allocation	PTZ cameras, video phones
PoE++ (IEEE 802.3bt Type 3/4)	60W (Type 3), 90W (Type 4), 4-pair power	Wireless APs, LED lighting, thin clients
UPoE (Cisco Universal PoE)	Up to 60W, proprietary protocol	Digital signage, high-power sensors

3. Structure and Components

PoE systems consist of Power Sourcing Equipment (PSE) and Powered Devices (PD). PSEs (e.g., switches, injectors) include controllers for power negotiation, isolation transformers, and protection circuits. PDs (e.g., cameras, APs) feature rectifiers, DC-DC converters, and signature detection circuits. External PSUs typically use AC-DC conversion, while internal PSUs integrate DC-DC modules.

4. Key Technical Specifications

Parameter	Importance
Power Output (W)	Determines device compatibility (e.g., 15.4W for VoIP phones)
Efficiency (80 PLUS Rating)	Reduces energy waste and operational costs
Input Voltage Range	Ensures adaptability to global power standards (100-240V AC)
Protection Features	Overcurrent, overvoltage, and short-circuit protection
Compliance Standards	IEEE 802.3af/at/bt, UL 62368-1

5. Application Fields

Enterprise networks: Wireless access points, VoIP phones
Surveillance: IP cameras, PTZ domes
Smart buildings: LED lighting control, IoT sensors
Healthcare: Medical monitoring devices, mobile carts

6. Leading Manufacturers and Products

Vendor	Representative Product
Cisco Systems	Catalyst 9200L Series PoE switches
Microchip Technology	PoE++ (90W) controllers for PDs
TP-Link	TalkTalk L2+ PoE managed switches
Dell Technologies	PowerEdge R760xa with integrated PoE+

7. Selection Recommendations

Match power output with device requirements (e.g., 90W for high-density APs)
Verify IEEE standard compatibility for interoperability
Evaluate thermal management for high-power PoE++ deployments
Consider managed PoE switches for remote monitoring and QoS control

8. Industry Trends

Future developments include higher power delivery (90W+), improved energy efficiency (80 PLUS Titanium), and integration with IoT ecosystems. Standards like IEEE 802.3bt enable multi-gigabit PoE for 5G small cells and edge computing devices. Smart PoE systems with AI-driven power allocation are emerging for dynamic load management in data centers.