Single Port PoE/PoE+/LTPoE++ PSE Controller
Features and Benefits
- Compliant with IEEE 802.3at Type 1 and 2
- 0.34Ω Total Channel Resistance
- 130mW/Port at 600mA
- Advanced Power Management
- 8-Bit Programmable Current Limit (ILIM)
- 7-Bit Programmable Overload Currents (ICUT)
- Fast Shutdown
- 14.5-Bit Port Current/Voltage Monitoring
- 2-Event Classification
- Very High Reliability 4-Point PD Detection
- 2-Point Forced Voltage
- 2-Point Forced Current
- High Capacitance Legacy Device Detection
- LTC4259A-1 and LTC4266 SW Compatible
- 1MHz I2C Compatible Serial Control Interface
- Midspan Backoff Timer
- Supports Proprietary Power Levels Above 25W
- Available in 38-Pin 5mm × 7mm QFN Package
The LTC4274 is a single power sourcing equipment controller designed for use in IEEE 802.3 Type 1 and Type 2 (high power) compliant Power over Ethernet systems. External power MOSFETs enhance system reliability and minimize channel resistance, cutting power dissipation and eliminating the need for heatsinks even at Type 2 power levels. External power components also allow use at very high power levels while remaining otherwise compatible with the IEEE standard. 80V-rated port pins provide robust protection against external faults.
The LTC4274 includes advanced power management features, including current and voltage readback and programmable ICUT and ILIM thresholds. Available C libraries simplify software development; an optional AUTO pin mode provides fully IEEE-compliant standalone operation with no software required. Proprietary 4-point PD detection circuitry minimizes false PD detection while supporting legacy phone operation. Midspan operation is supported with built-in 2-event classification and backoff timing. Host communication is via a 1MHz I2C serial interface.
The LTC4274 is available in a 5mm × 7mm QFN package that significantly reduces board space compared with competing solutions.
- PSE Switches/Routers
- PSE Midspans
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 (1)
Demonstration circuit 1567B features the LTC4274, a single power sourcing equipment (PSE) controller designed for use in IEEE 802.3 Type 1 (~13W at the PD) and Type 2 (~25.5W at the PD) compliant Power over Ethernet (PoE) systems. The LTC4274 is configured in the DC1567B as a midspan power injector where data comes in from an existing network system and out, along with power, to a powered device (PD). The LTC4274 autonomously detects and classifies a PD, turns power on to the port, and disconnects port power without the need for a microcontroller. A two second backoff timer supports the midspan configuration. A 55V nomical supply is recommended to power the demo board.
Tools & Simulations
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
Models for the following parts are available in LTspice:
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.