Analog DevicesLTC9101AUF-2A#PBFPower-Over-Ethernet-Controllers

LTC9101-2A: 12-/24-/48-Port IEEE 802.3 at PoE PSE Controller

The LTC9101-2A/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.

Key Features and Benefits

• •  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

Evaluation Board

The LTC9101-2A can be evaluated with either the EVAL-LTC9101-2 or DC3160A.

Block Diagrams and Tables