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.
Feature
- 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
- 1MHz I2C Compatible Serial Control Interface
- Pin or I2C Programmable PD Power Up to 71.3W
- Available in a 40-Lead 6mm × 6mm (LTC4292)QFN Package
