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

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.

  • 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

  • PoE PSE Switches/Routers
  • PoE PSE Midspans

Order Information
Part NumberPackageTempPrice(1-99)Price (1k)*
LTC4270AIUKG#PBF7x8 QFN-52I$14.71$10.30
LTC4270AIUKG#TRPBF7x8 QFN-52I$10.36
LTC4270BIUKG#PBF7x8 QFN-52I$12.86$9.00
LTC4270BIUKG#TRPBF7x8 QFN-52I$9.06
LTC4270CIUKG#PBF7x8 QFN-52I$12.86$9.00
LTC4270CIUKG#TRPBF7x8 QFN-52I$9.06
Demo Boards
Part NumberDescriptionPrice
DC1840CLTC4270B/LTC4271 Demo Board Kit | DC1680 + DC1682, 12-Port 25.5W PSE (req DC590)$300.00
Companion Boards
Part NumberDescriptionPrice
DC590BIsolated USB Serial Controller for Linear Technology QuikEval-Compatible Demo Boards$50.00
Reliability Data
Product Selector Card
LT Journal
Press Release
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