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
| Type | Functional Characteristics | Application Examples |
|---|
| PoE-PSE Controller | Manages power delivery from switches/injectors, supports multi-port management | Network switches, PoE midspans |
| PoE-PD Controller | Handles power reception in endpoint devices, supports DC-DC conversion | IP cameras, VoIP phones |
| Integrated Controller | Combines PSE/PD functions with MCU interfaces and protection circuits | Smart sensors, wireless APs |
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
| Parameter | Importance |
|---|
| Input Voltage Range (36-57V DC) | Ensures compatibility with PoE standards |
| Output Power Capability (up to 90W) | Determines supported device power class |
| Efficiency (>80%) | Impacts thermal performance and energy savings |
| Protection Features | Overcurrent, overtemperature, short-circuit |
| Communication Protocol Support | LLDP/IEEE 802.3 negotiation compatibility |
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
| Manufacturer | Representative Product | Key Features |
|---|
| TI (Texas Instruments) | TPS23880 | 8-port PSE controller with energy classification |
| Analog Devices | LTC4291 | Dual-channel PD controller with 90W support |
| STMicroelectronics | STPSE015 | Single-port PSE with automatic power allocation |
| Microchip | PoE++ Controller | Supports 100W Ultra PoE (UPOE) |
7. Selection Recommendations
- Match power requirements with IEEE 802.3bt Type 4 classification
- Verify backward compatibility with existing network infrastructure
- Evaluate protection features for harsh industrial environments
- Consider integration level (standalone vs. system-on-chip solutions)
- 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
