LTC4263 - Single IEEE 802.3af Compliant PSE Controller with Internal Switch


  • IEEE 802.3af Compliant
  • Operation from a Single 48V Supply
  • Fully Autonomous Operation without Microcontroller
  • Internal MOSFET with Thermal Protection
  • Power Management Works Across Multiple Ports with Simple RC Network
  • Precision Inrush Control with Internal Sense Resistor
  • Powered Device (PD) Detection and Classification
  • AC and DC Disconnect Sensing
  • Robust Short-Circuit Protection
  • Pin-Selectable Detection Backoff for Midspan PSEs
  • Classification Dependent ICUT Current Threshold
  • LED Driver Indicates Port On and Blinks Status Codes
  • Available in 14-Pin SO and 4mm × 3mm DFN Packages

Typical Application

LTC4263 Typical Application


The LTC4263 is an autonomous single-channel PSE controller for use in IEEE 802.3af compliant Power over Ethernet systems. It includes an onboard power MOSFET, internal inrush, current limit, and short-circuit control, IEEE 802.3af compliant PD detection and classification circuitry, and selectable AC or DC disconnect sensing. Onboard control algorithms provide complete IEEE 802.3af compliant operation without the need of a microcontroller. The LTC4263 simplifies PSE implementation, needing only a single 48V supply and a small number of passive support components.

Programmable onboard power management circuitry permits multiple LTC4263s to allocate and share power in multi-port systems, allowing maximum utilization of the 48V power supply—all without the intervention of a host processor. The port current limit can be configured to automatically adjust to the detected PD class. Detection backoff timing is configurable for either Endpoint or Midspan operation. Built-in foldback and thermal protection provide comprehensive fault protection.

An LED pin indicates the state of the port controlled by the LTC4263. When run from a single 48V supply, the LED pin can operate as a simple switching current source to reduce power dissipation in the LED drive circuitry.

The LTC4263 is available in 14-pin 4mm × 3mm DFN and 14-pin SO 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
LTC4263CDE#PBF 4x3 DFN-14 DE C 05-08-1708 Yes
LTC4263CDE#TRPBF 4x3 DFN-14 DE C 05-08-1708 Yes
LTC4263CS#PBF SO-14 S C 05-08-1610 (S14) Yes
LTC4263CS#TRPBF SO-14 S C 05-08-1610 (S14) Yes
LTC4263IDE#PBF 4x3 DFN-14 DE I 05-08-1708 Yes
LTC4263IDE#TRPBF 4x3 DFN-14 DE I 05-08-1708 Yes
LTC4263IS#PBF SO-14 S I 05-08-1610 (S14) Yes
LTC4263IS#TRPBF SO-14 S I 05-08-1610 (S14) Yes

LTC4263 Package Drawing
LTC4263 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
LTC4263CDE#PBF 4x3 DFN-14 C $4.21 $2.95 Yes
LTC4263CDE#TRPBF 4x3 DFN-14 C $3.01 Yes
LTC4263CS#PBF SO-14 C $4.21 $2.95 Yes
LTC4263CS#TRPBF SO-14 C $3.01 Yes
LTC4263IDE#PBF 4x3 DFN-14 I $5.05 $3.54 Yes
LTC4263IDE#TRPBF 4x3 DFN-14 I $3.60 Yes
LTC4263IS#PBF SO-14 I $5.05 $3.54 Yes
LTC4263IS#TRPBF SO-14 I $3.60 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
DC981A/B LTC4263 DC981A Midspan demoboard with DC981B Endspan plugin $100.00
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  • IEEE 802.3af Compliant Endpoint/Midspan PSEs
  • Single-Port or Multi-Port Power Injectors
  • Power Forwarders
  • Low-Port Count PSEs
  • Environment B PSEs
  • Standalone PSEs

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Design Tools

Linear Technology provides a variety of custom design simulation tools and device models to allow even novice designers to quickly and easily evaluate circuits using high performance switching regulators, amplifiers, data converters, filters and more. Please visit our Design Tools page to view and download:

  • LTspice - A powerful SPICE simulator, schematic capture and waveform viewer with enhancements and models for easing the simulation of switching regulators
  • LTpowerCAD - A complete power supply selection, synthesis and design tool
  • LTpowerPlay - A development environment supporting Linear Technology's Digital Power System Management (PSM) products
  • PScope & QuikEval - USB-based product demonstration and data acquisition system for use with our ADCs, DACs, and more
  • Linduino - Arduino compatible system for developing and distributing firmware libraries and example code
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