LTC4265 - IEEE 802.3 at High Power PD Interface Controller with 2-Event Classification Recognition

The LTC®4265 is a 3rd generation Powered Device (PD) Interface controller intended for IEEE 802.3at high power Power-over-Ethernet (PoE) applications up to 25.5W. By supporting 1-event and 2-event classification signaling as defined by IEEE 802.3, the LTC4265 can be used in a wide range of product configurations. A 100V MOSFET isolates the DC/DC converter during detection and classification, and provides 100mA inrush current for a smooth power-up transition. The LTC4265 also includes complementary power good outputs, an on-board signature resistor, undervoltage/overvoltage lockout and comprehensive thermal protection. All Linear Technology PD solutions include a shutdown pin with signature corrupt to provide flexible auxiliary power options.

The LTC4265 PD interface controller can be used along with a variety of DC/DC converter products to provide a complete, cost effective power solution for high power PD applications.

The LTC4265 is available in the space-saving low profile (4mm × 3mm) DFN package and is drop-in compatible with the LTC4264.

  • IEEE 802.3af/at Powered Device (PD) Controller
  • IEEE 802.3at 2-event Classification Signaling
  • Programmable Classification Current
  • Flexible Auxiliary Power Support Using SHDN Pin
  • Rugged 100V Onboard MOSFET with 100mA Inrush Current Limit.
  • Complementary Power Good Outputs
  • Onboard Signature Resistor
  • Comprehensive Thermal Protection
  • Undervoltage and Overvoltage Lockout
  • 12-Lead, 4mm × 3mm DFN Package
Typical Application

  • 802.11n Access Points
  • High Power VoIP Video Phones
  • RFID Reader Systems
  • PTZ Security Cameras and Surveillance Equipment
Order Information
Part NumberPackageTempPrice(1-99)Price (1k)*
LTC4265CDE#PBF4x3 DFN-12C$2.57$1.80
LTC4265CDE#TRPBF4x3 DFN-12C$1.86
LTC4265IDE#PBF4x3 DFN-12I$3.07$2.15
LTC4265IDE#TRPBF4x3 DFN-12I$2.21
Demo Boards
Part NumberDescriptionPrice
DC1415ALTC4265 IEEE802.3at PD Controller$75.00
Reliability Data
Product Selector Card
LT Journal
Press Release
Related Product
LTC4265 - IEEE 802.3 at High Power PD Interface Controller with 2-Event Classification Recognition
R413 Reliability Data
PoE PD Controllers
PoE+ for the Power Hungry
Power over Ethernet Solutions
Jan 2009 -PD Interface for PoE+ Includes 25.5W Classification and Protection Features in a Low Profile 4mm × 3mm DFN
LTC4265 - 高功率 PD 控制器符合 IEEE 802.3at PoE+ 标准
LTC4265 Footprints and Symbols