LTC4269-1 - IEEE 802.3at High Power PD and No-Opto Flyback Controller with AUX Support

The LTC4269-1 is an integrated Powered Device (PD) controller and switching regulator intended for high power IEEE 802.3at and 802.3af applications. The LTC4269-1 is targeted for high efficiency, single and multioutput applications from 10W to 25W. By supporting both 1-event and 2-event classifications, as defined by the IEEE, the LTC4269-1 can be used in a wide range of product configurations.

The LTC4269-1 synchronous, current mode, flyback controller generates multiple supply rails in a single conversion step providing for the highest system efficiency while maintaining tight regulation across all outputs. The LTC4269-1 includes Linear Technology’s patented No-Opto feedback topology to provide full IEEE 802.3 isolation without the need of an opto-isolator circuit. A true soft-start function allows graceful ramp-up of all output voltages.

All Linear Technology PD solutions include a shutdown pin to provide flexible auxiliary power options. The LTC4269-1 can accommodate adaptor voltages from 18V to 60V and supports both PoE or aux dominance options. The LTC4269-1 is available in a space saving 32-pin DFN package.

  • 25.5W IEEE 802.3at Compliant (Type 2) PD
  • Integrated State-of-the-Art Synchronous Flyback Controller – Isolated Power Supply Efficiency >92% – 88% Efficiency Including Diode Bridge and
  • Hot Swap™ FET
  • Flexible Integrated Auxiliary Power Support
  • Superior EMI Performance
  • Robust 100V 0.7Ω (Typ) Integrated Hot Swap MOSFET
  • IEEE 802.3at High Power Available Indicator
  • Integrated Signature Resistor and Programmable Class Current
  • Undervoltage, Overvoltage and Thermal Protection
  • Short-Circuit Protection with Auto-Restart
  • Programmable Soft-Start and Switching Frequency
  • Complementary Power Good Indicators
  • Thermally Enhanced 7mm × 4mm DFN Package
Typical Application
  • VoIP Phones with Advanced Display Options
  • Dual-Radio Wireless Access Points
  • PTZ Security Cameras
  • RFID Readers
  • Industrial Controls
Order Information
Part NumberPackageTempPrice(1-99)Price (1k)*
LTC4269CDKD-1#PBF7x4 DFN-32C$3.43$2.40
LTC4269CDKD-1#TRPBF7x4 DFN-32C$2.46
LTC4269IDKD-1#PBF7x4 DFN-32I$4.11$2.88
LTC4269IDKD-1#TRPBF7x4 DFN-32I$2.94
Demo Boards
Part NumberDescriptionPrice
DC1335B-BLTC4269-1 | PoE Powered Device w/48V Isolated Auxiliary, Vout = 5V, Iout = 5A$75.00
DC1335B-CLTC4269-1 | PoE Powered Device w/48V Isolated Auxiliary, Vout = 12V, Iout = 2A$75.00
Reliability Data
Product Selector Card
LT Journal
Press Release
Related Product
LTC4269-1 - IEEE 802.3at PD with Synchronous No-Opto Flyback Controller
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
LTC4269-1 Footprints and Symbols