SLVS646B September   2006  – November 2018 TPS2376-H

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Application Circuit
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 ESD Ratings IEC
    4. 7.4 Recommended Operating Conditions
    5. 7.5 Thermal Information
    6. 7.6 Electrical Characteristics
    7. 7.7 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Undervoltage Lockout (UVLO)
      2. 8.3.2 Programmable Inrush Current Limit and Fixed Operational Current Limit
      3. 8.3.3 Power Good
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Internal Thresholds
      2. 9.1.2 Detection
      3. 9.1.3 Classification
    2. 9.2 Typical Application
      1. 9.2.1 External Components
        1. 9.2.1.1 Detection Resistor and UVLO Divider
        2. 9.2.1.2 Magnetics
        3. 9.2.1.3 Input Diodes or Diode Bridges
        4. 9.2.1.4 Input Capacitor
        5. 9.2.1.5 Load Capacitor
        6. 9.2.1.6 Transient Suppressor
  10. 10Power Supply Recommendations
    1. 10.1 Maintain Power Signature
    2. 10.2 DC/DC Converter Startup
    3. 10.3 Auxiliary Power Source ORing
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
    3. 11.3 Thermal Protection
    4. 11.4 ESD
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Community Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

9.2.1.2 Magnetics

A high-power PoE system places additional burden on power extraction from data pairs. Data transmission properties must be maintained while carrying higher current and withstanding higher difference current between the conductors in a pair. This difference current is the result of unbalanced resistances between the conductors of a pair (see IEEE 802.3af annex 33E).

Either a higher current center-tapped transformer as shown in Figure 13, or the addition of a center-tapped inductor, can be implemented. Proper termination is required around the transformer to provide correct impedance matching and to avoid radiated and conducted emissions.