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


  • 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

LTC4269-2 Typical Application


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.


CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.

For complete and up to date package information and drawings, please refer to our packaging page

Part Number Package Code Temp Package
LTC4269CDKD-2#PBF 7x4 DFN-32 DKD C 05-08-1734 Yes
LTC4269CDKD-2#TRPBF 7x4 DFN-32 DKD C 05-08-1734 Yes
LTC4269IDKD-2#PBF 7x4 DFN-32 DKD I 05-08-1734 Yes
LTC4269IDKD-2#TRPBF 7x4 DFN-32 DKD I 05-08-1734 Yes

LTC4269-2 Package Drawing

Order Info

  • Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
  • Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
  • Please refer to our general ordering information or the product datasheet for more details

Package Variations and Pricing

Part Number Package Temp Price
LTC4269CDKD-2#PBF 7x4 DFN-32 C $3.71 $2.60 Yes
LTC4269CDKD-2#TRPBF 7x4 DFN-32 C $2.65 Yes
LTC4269IDKD-2#PBF 7x4 DFN-32 I $4.46 $3.12 Yes
LTC4269IDKD-2#TRPBF 7x4 DFN-32 I $3.18 Yes
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* The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Linear Technology sales office or authorized distributor.

Demo Boards

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

Part Number Description Price Documentation
DC1351B LTC4269-2 | PoE Powered Device w/48V Isolated Auxiliary, Vout = 5V, Iout = 5A $50.00
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Click here to view our complete list of demo boards


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