LTC4269-2 - IEEE 802.3at High Power PD and Synchronous Forward Controller with AUX Support

The LTC4269-2 is an integrated Powered Device (PD) interface and power supply controller featuring 2-event classification signaling, flexible auxiliary power options, and a power supply controller suitable for synchronously rectified forward supplies. These features make the LTC4269-2 ideally suited for an IEEE802.3at PD application.

The PD controller features a 100V MOSFET that isolates the power supply during detection and classification, and provides 100mA inrush current limit. Also included are power good outputs, an undervoltage/overvoltage lockout and thermal protection. The current mode forward controller allows for synchronous rectification, resulting in an extremely high efficiency, green product. Soft-start for controlled output voltage start-up and fault recovery is included. Programmable frequency over 100kHz to 500kHz allows flexibility in efficiency vs size and low EMI.

  • 25.5W IEEE 802.3at Compliant (Type-2) PD
  • PoE+ 2-Event Classification
  • IEEE 802.3at High Power Available Indicator
  • Integrated State-of-the-Art Synchronous Forward
  • Controller – Isolated Power Supply Efficiency >94%
  • Flexible Auxiliary Power Interface
  • Superior EMI Performance
  • Robust 100V 0.7Ω (Typ) Integrated Hot Swap™ MOSFET
  • Integrated Signature Resistor, Programmable Class Current, UVLO, OVLO and Thermal Protection
  • Short-Circuit Protection with Auto-Restart
  • Programmable Switching Frequency from 100kHz to 500kHz
  • Thermally Enhanced 7mm × 4mm DFN Package
Typical Application
  • IP Phones with Large Color Screens
  • Dual Radio 802.11n Access Points
  • PTZ Security Cameras
Order Information
Part NumberPackageTempPrice(1-99)Price (1k)*
LTC4269CDKD-2#PBF7x4 DFN-32C$3.71$2.60
LTC4269CDKD-2#TRPBF7x4 DFN-32C$2.65
LTC4269IDKD-2#PBF7x4 DFN-32I$4.46$3.12
LTC4269IDKD-2#TRPBF7x4 DFN-32I$3.18
Demo Boards
Part NumberDescriptionPrice
DC1351BLTC4269-2 | PoE Powered Device w/48V Isolated Auxiliary, Vout = 5V, Iout = 5A$50.00
Reliability Data
Product Selector Card
LT Journal
Press Release
Related Product
LTC4269-2 - IEEE 802.3at High Power PD and Synchronous Forward Controller with AUX Support
R535 Reliability Data
PoE PD Controllers
PoE+ for the Power Hungry
Power over Ethernet Solutions
September 2009 - PD Controller ICs with Integrated Flyback or Forward Controllers Meet Demands of 25.5W PoE+
具内置开关的大功率受电设备控制器符合 IEEE 802.3at PoE+ 标准
LTC4269-2 Footprints and Symbols