LTC4291/LTC4292 PoE++ PSE Digital Controller

Analog Devices' LTC4291 and LTC4292 are 4-port power sourcing equipment (PSE) controllers designed for use in IEEE 802.3bt Type 3 and 4 compliant Power over Ethernet (PoE) systems. They are designed to power compliant 802.3af, 802.3at, and 802.3bt PDs. The LTC4291 and LTC4292 chipset deliver lowest-in-industry heat dissipation by utilizing low-R_DS(ON) external MOSFETs and 0.15 Ω sense resistance per power channel. A transformer-isolated communication protocol replaces expensive optocouplers and complex isolated 3.3 V supply, resulting in significant BOM cost savings.

Advanced power management features include per-port 14-bit current monitoring, programmable current limit, and versatile, fast shut-down of preselected ports. Advanced power management host software is available under a no-cost license. PD detection uses a proprietary multipoint detection mechanism ensuring excellent immunity from false PD identification. Auto-class and 5-event physical classification are supported. The LTC4291 and LTC4292 include an I²C serial interface operable up to 1 MHz. These controllers are pin or I²C programmable to negotiate PD delivered power up to 71.3 W. The LTC4191 and LTC4192 are ideal for PoE PSE switches, routers, and midspans.