LTC4267 - Power over Ethernet IEEE 802.3af PD Interface with Integrated Switching Regulator


  • Complete Power Interface Port for IEEE 802.3af Powered Device (PD)
  • Onboard 100V, 400mA UVLO Switch
  • Precision Dual Level Inrush Current Limit
  • Integrated Current Mode Switching Regulator
  • Onboard 25kΩ Signature Resistor with Disable
  • Programmable Classification Current (Class 0-4)
  • Thermal Overload Protection
  • Power Good Signal
  • Integrated Error Amplifier and Voltage Reference
  • Low Profile 16-Pin SSOP and 3mm × 5mm DFN Packages

Typical Application

LTC4267 Typical Application


The LTC4267 combines an IEEE 802.3af compliant Powered Device (PD) interface with a current mode switching regulator, providing a complete power solution for PD applications. The LTC4267 integrates the 25kΩ signature  resistor, classification current source, thermal overload protection, signature disable and power good signal along with an undervoltage lockout optimized for use with the IEEE required diode bridge. The precision dual level input current limit allows the LTC4267 to charge large load capacitors and interface with legacy PoE systems.

The current mode switching regulator is designed for driving a 6V rated N-channel MOSFET and features programmable slope compensation, soft-start, and constant frequency operation, minimizing noise even with light loads. The LTC4267 includes an onboard error amplifier and voltage reference allowing use in both isolated and nonisolated configurations.

The LTC4267 is available in space saving, low profile 16-pin SSOP or DFN packages.


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
LTC4267CDHC#PBF 5x3 DFN-16 DHC C 05-08-1706 Yes
LTC4267CDHC#TRPBF 5x3 DFN-16 DHC C 05-08-1706 Yes
LTC4267CGN#PBF SSOP-16 GN C 05-08-1641 (GN16) Yes
LTC4267CGN#TRPBF SSOP-16 GN C 05-08-1641 (GN16) Yes
LTC4267IDHC#PBF 5x3 DFN-16 DHC I 05-08-1706 Yes
LTC4267IDHC#TRPBF 5x3 DFN-16 DHC I 05-08-1706 Yes
LTC4267IGN#PBF SSOP-16 GN I 05-08-1641 (GN16) Yes
LTC4267IGN#TRPBF SSOP-16 GN I 05-08-1641 (GN16) Yes

LTC4267 Package Drawing
LTC4267 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
LTC4267CDHC#PBF 5x3 DFN-16 C $2.92 $2.20 Yes
LTC4267CDHC#TRPBF 5x3 DFN-16 C $2.30 Yes
LTC4267CGN#PBF SSOP-16 C $2.75 $2.10 Yes
LTC4267CGN#TRPBF SSOP-16 C $2.16 Yes
LTC4267IDHC#PBF 5x3 DFN-16 I $3.50 $2.65 Yes
LTC4267IDHC#TRPBF 5x3 DFN-16 I $2.75 Yes
LTC4267IGN#PBF SSOP-16 I $3.33 $2.55 Yes
LTC4267IGN#TRPBF SSOP-16 I $2.61 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
DC1145B LTC4267CDHC | PoE Powered Device w/12V Isolated Auxiliary, Vout = 12V @ 0.9A $75.00
DC804B-A LTC4267CDHC | RJ-45 Ethernet Output, Vout = 3.3V @ 1.0A $75.00
DC859A LTC4267IDHC Triple-Output PD for PoE $75.00
DC917A LTC4267| PoE to 3.3V@2.6A Isolated $75.00
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Click here to view our complete list of demo boards


  • IP Phone Power Management
  • Wireless Access Points
  • Security Cameras
  • Power over Ethernet

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