1. Overview

Power Over Ethernet (PoE) Controllers are specialized Power Management ICs (PMICs) that enable power delivery and data transmission over Ethernet cables. Defined by IEEE 802.3af/at/bt standards, these controllers manage power negotiation, detection, classification, and protection between Power Sourcing Equipment (PSE) and Powered Devices (PD). Their importance in modern technology lies in simplifying deployment of networked devices by eliminating separate power supplies, enabling applications in IoT, smart buildings, and industrial automation.

2. Major Types and Functional Classification

3. Structure and Components

Typical PoE controllers feature: - 16-48 pin QFN/TSSOP packaging - Internal precision sensing amplifiers - Digital control logic for IEEE standard compliance - MOSFET drivers for power switching - Thermal shutdown and OVP/UVP protection modules - I C/SPI interfaces for system integration

4. Key Technical Specifications

5. Application Areas

• Telecommunications: VoIP phones, fiber modems
• Security Systems: PTZ IP cameras, access control readers
• Industrial IoT: Wireless sensors, process controllers
• Smart Buildings: LED lighting systems, HVAC controls
• Networking: Wireless access points, Ethernet extenders

6. Leading Manufacturers and Products

7. Selection Recommendations

1. Match power requirements with IEEE 802.3bt Type 4 classification
2. Verify backward compatibility with existing network infrastructure
3. Evaluate protection features for harsh industrial environments
4. Consider integration level (standalone vs. system-on-chip solutions)
5. Analyze thermal management requirements for continuous operation

8. Industry Trends

Key development trends include: - Increased adoption of 90W+ PoE for 5G small cells and PTZ cameras - Integration with AI-powered power management systems - Enhanced energy efficiency (>90%) for green computing - Miniaturization for space-constrained applications - Expansion into automotive (PoE for AVB networks) and medical device sectors - Development of intelligent PoE controllers with real-time power monitoring