The LTC9101-2A/LTC9102chipset is a (up to) 48-port power sourcing equipment (PSE) controller designed for use in IEEE 802.3at Type 1 and 2 compliant Power over Ethernet (PoE) systems. The LTC9101-2A/LTC9102 is designed to power compliant 802.3af and 802.3at PDs. The LTC9101-2A/LTC9102 chipset delivers lowest-in-industry heat dissipation using low RDS(ON)external MOSFETs and 0.1Ω sense resistance per power channel. A transformer-isolated communication protocol replaces expensive optocouplers and a complex isolated 3.3V supply, resulting in significant bill of materials (BOM) cost savings.Advanced power management features include per-port 14‑bit current/voltage monitoring, programmable current limits, and versatile fast shutdown of preselected ports. PD detection uses a proprietary multipoint detection mechanism, ensuring excellent immunity from false PD identification. 1-event and 2-event physical classification are supported. The LTC9101-2A/LTC9102 includes an I2C serial interface operable up to 1MHz. The LTC9101-2A/LTC9102 is pin or I2C programmable to negotiate PD-delivered power up to 25.5W.APPLICATIONSPoE PSE Switches/Routers and Midspans