LTC4271 Series

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

Catalog

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

Part	Type	Mounting Type	Standards	Internal Switch(s)	Auxiliary Sense	Voltage - Supply [Max]	Voltage - Supply [Min]	Operating Temperature [Max]	Operating Temperature [Min]	Package / Case	Current - Supply	Supplier Device Package
Analog Devices LTC4271IUF#PBF	Controller (PSE)	Surface Mount	802.3at (PoE)			3.6 V	3 V	85 °C	-40 °C	24-WFQFN Exposed Pad	10 mA	24-QFN (4x4)

Catalog

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

Key Features

• 12 Independent PSE Channels

• Compliant with IEEE 802.3at Type 1 and 2

• Chipset Provides Electrical IsolationReduced BOM CostEliminates up to 6 High Speed Opto-CouplersEliminates Isolated 3.3V Power Supply

• Reduced BOM Cost

• Eliminates up to 6 High Speed Opto-Couplers

• Eliminates Isolated 3.3V Power Supply

• Low Power Dissipation0.25Ω Sense Resistance Per Channel

• 0.25Ω Sense Resistance Per Channel

• Very High Reliability 4-Point PD Detection2-Point Forced Voltage2-Point Forced Current

• 2-Point Forced Voltage

• 2-Point Forced Current

• VEEand VPORTMonitoring

• 1 Second Rolling IPORTAveraging

• Supports 2-Pair and 4-Pair Output Power

• 1MHz I2C Compatible Serial Control Interface

• Available In Three Power GradesA-Grade – LTPoE++™38.7W to 90WB-Grade – PoE+ 25.5WC-Grade – PoE 13W

• 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

Description

TheLTC4270/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.APPLICATIONSPoE PSE Switches/RoutersPoE PSE Midspans