DESCRIPTION

The LTC®9101-2 chipset is a 12/24-port power sourcing

equipment (PSE) controller designed for use in IEEE 802.3bt

Type 3 and 4 compliant Power over Ethernet (PoE) systems.

The LTC9101-2/LTC9102 is designed to power compliant

802.3af, 802.3at, and 802.3bt PDs. The LTC9101-2/LTC9102

chipset delivers lowest-in-industry heat dissipation by utilizing

low RDS(ON) external MOSFETs and 0.1Ω sense resistance

per power channel. A transformer-isolated communication

protocol replaces expensive opto-couplers and complex isolated

3.3V supply, resulting in significant BOM cost savings.

Advanced power management features include per-port

14‑bit current/voltage monitoring, programmable power

limits, and versatile fast shut down of preselected ports.

An advanced power management host software layer is

available. PD detection uses a proprietary multipoint detection

mechanism ensuring excellent immunity from false PD

identification. Autoclass and 5-event physical classification

are supported. The LTC9101-2/LTC9102 includes an

I2C serial interface operable up to 1MHz. The LTC9101-2/

LTC9102 is pin or I2C programmable to negotiate PD delivered

power up to 71.3W.

FEATURES

- Fully Compliant IEEE 802.3bt Type 3 and 4 PSE

- Up to 24 PSE Ports with Two Power Channels per Port

- +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

- Connection Check Distinguishes Single-

Signature and Dual-Signature PDs

- Continuous Per-Port Voltage and Current Monitoring

- 1MHz I2C Compatible Serial Control Interface

- Pin or I2C Programmable PD Power

- Available in a 24-Lead 4mm × 4mm (LTC9101‑2) and

64-Lead 7mm × 11mm (LTC9102) QFN Packages

APPLICATIONS

- PoE PSE Switches/Routers and Midspans