LTC4270/LTC4271 - 12-Port PoE/PoE+/LTPoE++ PSE Controller


  • 12 Independent PSE Channels
  • Compliant with IEEE 802.3at Type 1 and 2
  • Chipset Provides Electrical Isolation
  • Reduced BOM Cost
  • Eliminates up to 6 High Speed Opto-Couplers
  • Eliminates Isolated 3.3V Power Supply
  • Low Power Dissipation
  • 0.25Ω Sense Resistance Per Channel
  • Very High Reliability 4-Point PD Detection
  • 2-Point Forced Voltage
  • 2-Point Forced Current
  • VEE and VPORT Monitoring
  • 1 Second Rolling IPORT Averaging
  • Supports 2-Pair and 4-Pair Output Power
  • 1MHz I2C Compatible Serial Control Interface
  • Available In Three Power Grades
  • A-Grade – LTPoE++™ 38.7W to 90W
  • B-Grade – PoE+ 25.5W
  • C-Grade – PoE 13W
  • Available In 52-Lead 7mm × 8mm (LTC4270) and 24‑Lead 4mm × 4mm (LTC4271) QFN Packages

Typical Application

LTC4270 Typical Application
LTC4270 Typical Application


The LTC®4270/LTC4271 chipset is a 12-port power sourcing equipment (PSE) controller designed for use in IEEE 802.3at Type 1 and Type 2 (high power) compliant Power over Ethernet (PoE) systems. Transformer-isolated communication protocol replaces expensive opto-couplers and complex isolated 3.3V supply resulting in significant BOM cost savings. The LTC4270/LTC4271 chipset delivers lowest-in-industry heat dissipation by utilizing low-RDS(ON) external MOSFETs and 0.25Ω sense resistors.

Advanced power management features include per-port 12‑bit current monitoring ADCs, DAC-programmable current limit, and versatile fast shut-down of preselected ports. Advanced power management host software is available under a no-cost license. PD discovery uses a proprietary dual-mode 4-point detection mechanism ensuring excellent immunity from false PD detection. Midspan PSEs are supported with 2-event classification and a 2 second backoff timer. The LTC4270/LTC4271 includes an I2C serial interface operable up to 1MHz.

The LTC4270/LTC4271 is available in multiple power grades allowing delivered PD power up to 90W.


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
LTC4270AIUKG#PBF 7x8 QFN-52 UKG I 05-08-1729 Yes
LTC4270AIUKG#TRPBF 7x8 QFN-52 UKG I 05-08-1729 Yes
LTC4270BIUKG#PBF 7x8 QFN-52 UKG I 05-08-1729 Yes
LTC4270BIUKG#TRPBF 7x8 QFN-52 UKG I 05-08-1729 Yes
LTC4270CIUKG#PBF 7x8 QFN-52 UKG I 05-08-1729 Yes
LTC4270CIUKG#TRPBF 7x8 QFN-52 UKG I 05-08-1729 Yes

LTC4270 Package Drawing
LTC4270 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
LTC4270AIUKG#PBF 7x8 QFN-52 I $14.71 $10.30 Yes
LTC4270AIUKG#TRPBF 7x8 QFN-52 I $10.36 Yes
LTC4270BIUKG#PBF 7x8 QFN-52 I $12.86 $9.00 Yes
LTC4270BIUKG#TRPBF 7x8 QFN-52 I $9.06 Yes
LTC4270CIUKG#PBF 7x8 QFN-52 I $12.86 $9.00 Yes
LTC4270CIUKG#TRPBF 7x8 QFN-52 I $9.06 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
DC1840C LTC4270B/LTC4271 Demo Board Kit | DC1680 + DC1682, 12-Port 25.5W PSE (req DC590) $300.00
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Companion Boards

Part Number Description Price Documentation
DC590B Isolated USB Serial Controller for Linear Technology QuikEval-Compatible Demo Boards $50.00
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Click here to view our complete list of demo boards


  • PoE PSE Switches/Routers
  • PoE PSE Midspans

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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
  • LinearLab Tools - A collection of Matlab and Python programs that provide direct access to Linear Technology’s data converter evaluation boards
  • And More!

Technical Support