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

Features

  • 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

Description

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.

Packaging

For complete and up to date package information and drawings, please refer to our packaging page

QFN-52, QFN-24

LTC4270 Package Drawing
LTC4270 Package Drawing

Order Info

Package Variations and Pricing

Part Number Package Pins Temp Price (1-99) Price (1k)* RoHS Data
LTC4270AIUKG#PBF QFN 52 I $14.71 $10.30 View
LTC4270AIUKG#TRPBF QFN 52 I $10.36 View
LTC4270BIUKG#PBF QFN 52 I $12.86 $9.00 View
LTC4270BIUKG#TRPBF QFN 52 I $9.06 View
LTC4270CIUKG#PBF QFN 52 I $12.86 $9.00 View
LTC4270CIUKG#TRPBF QFN 52 I $9.06 View
Buy NowRequest Samples
* 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
DC1840A LTC4270B/LTC4271: (DC1680 + DC1682) 12-Port 25.5W Demo Kit (req DC590) $300.00
Buy Now

Companion Boards

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

Applications

  • PoE PSE Switches/Routers
  • PoE PSE Midspans

Product Notifications

Please login to your MyLinear account for notifications of datasheet updates, new document releases and LTspice model announcements for your favorite products. If you do not have a MyLinear account you may Sign Up Now.

Forgot your password? Click here.
Need help? Email mylinear@linear.com with questions and comments.

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:

Technical Support