Features and Benefits
- Compliant with IEEE 802.3at Type 1 and 2
- Supports LTPoE++® Up to 90W
- Supports Dual-Signature PDs
- Fully Autonomous Operation without Microcontroller
- Very Low Power Dissipation
- 0.1Ω Sense Resistance
- Low RDS(ON) External MOSFET
- Very High Reliability 4-Point PD Detection
- 2-Point Forced Voltage and Forced Current
- Robust Short-Circuit Protection
- Cable Surge Protected ±80V OUT pin
- Classification Dependent ICUT and ILIM Current Thresholds
- Supports 2-Pair and 4-Pair Output Power
- UltraPWR Mode Supports Custom PDs up to 123W
- Pin-Selectable Detection Backoff Timer for Midspans
- Pin Programmable Legacy PD Detection
- Pin Programmable Maximum Power Mode
- Status LED Pin
- Available in 20-Pin QFN and 16-Pin SO Packages
The LTC4279 is an autonomous single port power sourcing equipment (PSE) controller designed for use in IEEE 802.3at Type 1, Type 2 and LTPoE++ compliant Power over Ethernet (PoE) systems. The LTC4279 provides fully autonomous IEEE 802.3 and LTPoE++ compliant operation without a microcontroller. The LTC4279 simplifies PSE implementation, requiring only a single supply and a small number of passive support components.
The LTC4279 delivers lowest-in-industry heat dissipation by utilizing a low-RDS(ON) external MOSFET and a 0.1Ω sense resistor, eliminating the need for expensive heat sinks and increasing efficiency.
PD discovery uses a proprietary dual-mode 4-point detection mechanism ensuring excellent immunity from false PD detection. Midspan PSEs are supported with physical layer classification and a 2.5 second backoff timer.
Legacy and custom PDs are supported with pin-selectable LEGACY and UltraPWR modes. LEGACY mode detects and powers pre-IEEE specification PDs. UltraPWR mode aggressively turns on and powers custom PDs requiring high inrush and/or operational currents.
- PoE PSE Endpoints (Switch/Router)
- PoE Midspan Power Injectors
- Power Forwarders
- Femto Cells
- Security Systems
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (2)
Demonstration Circuit 2579A features the LTC4279, an autonomous single port power sourcing equipment (PSE) controller, configured in its UltraPWR mode. UltraPWR mode aggressively turns on and powers custom high power PDs requiring high inrush and/or operational currents.
Demonstration circuit 2541A features the LTC4279, an autonomous single port Power Sourcing Equipment (PSE) controller for use in IEEE 802.3at Type 1, Type 2 and LTPoE++® compliant Power over Ethernet (PoE) systems. The LTC4279 simplifies IEEE and LTPoE++ PSE implementation, requiring only a 45-57V supply and a small number of passive support components.
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.