DESCRIPTION

The LTC?9101-2A/LTC9102 chipset 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.

FEATURES

? Fully Compliant IEEE 802.3at Type 1 and 2 PSE

? Up to 48 PSE Ports

? Industry-Standard Register Map

? +80V/–20V Tolerant Port-Facing Pins

? ECC-Protected eFlash and Data RAMs

? Low Power Path Dissipation per Channel

? 100mΩ Sense Resistance

? 30mΩ or Lower MOSFET RDS(ON)

? Chipset Provides Electrical Isolation

? Eliminates Optos and Isolated 3.3V Supply

? Very High Reliability Multipoint PD Detection

? Continuous Per-Port Voltage and Current Monitoring

? 1MHz I2C Compatible Serial Control Interface

? Pin or I2C Programmable PD Power

? Available in 24-Lead 4mm × 4mm (LTC9101?2A) and 64-Lead

7mm × 11mm (LTC9102) QFN Packages

APPLICATIONS

? PoE PSE Switches/Routers and Midspans