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 * 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 https://elecena.pl/product/1665765/12-port-poe-poe-ltpoe-pse-controller 2011-04-17 https://elecena.pl/product/1665765/12-port-poe-poe-ltpoe-pse-controller 2012-03-06 https://elecena.pl/product/1665765/12-port-poe-poe-ltpoe-pse-controller 2025-01-20