PoE++ PSE Digital Controller

The LTC4292/LTC4291 chipset is a 4-port power sourcing equipment (PSE) controller designed for use in IEEE 802.3bt Type 3 and 4 compliant Power over Ethernet (PoE) systems. The LTC4292/LTC4291 is designed to power compliant 802.3af, 802.3at, and 802.3bt PDs. The LTC4292/LTC4291 chipset delivers lowest-in-industry heat dissipation by utilizing low-RDS(ON) external MOSFETs and 0.15Ω 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 perport 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. Autoclass and 5-event physical classification are supported. The LTC4292/LTC4291 includes an I2C serial interface operable up to 1MHz. The LTC4292/LTC4291 is pin or I2C programmable to negotiate PD delivered power up to 71.3W.

* Four PSE Ports

* Two Power Channels Per Port

* Fully Compliant IEEE 802.3bt Type 3 and 4 PSE

* Compliant Support for Type 1, 2, 3, and 4 PDs

* Low Power Path Dissipation per Channel

* 150mΩ 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, Dedicated Per-Port Power and Current Monitoring

* Per-Port Power Policing

* 1MHzI2C Compatible Serial Control Interface

* Pin or I2C Programmable PD Power Up to 71.3W

* Available in a 24-Lead 4mm × 4mm QFN Package