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