LTC4271IUF#PBF

LINEAR TECHNOLOGY  LTC4271IUF#PBF  芯片, PSE控制器, 12端口, 45-57V, I2C, 24QFN

The is a 12-port Power Sourcing Equipment PSE Controller designed for use in IEEE 802.3 at 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. This chipset delivers lowest-in-industry heat dissipation by utilizing low-RDSON external MOSFETs and 0.25R 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.

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12 Independent PSE channels

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Compliant with IEEE 802.3 at type 1 and 2

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Chipset provides electrical isolation

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Eliminates up to 6 high speed opto-couplers

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Eliminates isolated 3.3V Power supply

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Low power dissipation

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0.25R Sense resistance per channel

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Very high reliability 4-Point PD detection

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2-point Forced voltage

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2-point Forced current

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VEE and VPORT Monitoring