Overview

Features and Benefits

  • 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

Product Details

The LTC4270/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.

Applications

  • PoE PSE Switches/Routers
  • PoE PSE Midspans

Product Lifecycle icon-recommended Production

At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.

Evaluation Kits (1)

Product Recommendations

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Design Resources

ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well.  "Zero defects" for shipped products is always our goal.

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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 Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.


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Evaluation Boards Pricing displayed is based on 1-piece.
Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.