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

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.

  • 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
  • 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

Order Information
Part NumberPackageTempPrice(1-99)Price (1k)*
LTC4263CDE#PBF4x3 DFN-14C$4.21$2.95
LTC4263CDE#TRPBF4x3 DFN-14C$3.01
LTC4263IDE#PBF4x3 DFN-14I$5.05$3.54
LTC4263IDE#TRPBF4x3 DFN-14I$3.60
Demo Boards
Part NumberDescriptionPrice
DC981A/BLTC4263 DC981A Midspan demoboard with DC981B Endspan plugin$100.00
Design Note
Reliability Data
Product Selector Card
Press Release
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