Power over Ethernet IEEE 802.3af PD Interface with Integrated Switching Regulator
Features and Benefits
- Complete Power Interface Port for IEEE 802®.3af Powered Device (PD)
- Onboard 100V, 400mA UVLO Switch
- Precision Dual Level Inrush Current Limit
- Integrated Current Mode Switching Regulator
- Onboard 25kΩ Signature Resistor with Disable
- Programmable Classiﬁcation Current (Class 0-4)
- Thermal Overload Protection
- Power Good Signal
- Integrated Error Ampliﬁer and Voltage Reference
- Low Proﬁle 16-Pin SSOP and 3mm × 5mm DFN Packages
The LTC4267 combines an IEEE 802.3af compliant Powered Device (PD) interface with a current mode switching regulator, providing a complete power solution for PD applications. The LTC4267 integrates the 25kΩ signature resistor, classiﬁcation current source, thermal overload protection, signature disable and power good signal along with an undervoltage lockout optimized for use with the IEEE-required diode bridge. The precision dual level input current limit allows the LTC4267 to charge large load capacitors and interface with legacy PoE systems.
The current mode switching regulator is designed for driving a 6V rated N-channel MOSFET and features programmable slope compensation, soft-start, and constant frequency operation, minimizing noise even with light loads. The LTC4267 includes an onboard error ampliﬁer and voltage reference allowing use in both isolated and nonisolated conﬁgurations.
The LTC4267 is available in space saving, low proﬁle 16-pin SSOP or DFN packages.
- IP Phone Power Management
- Wireless Access Points
- Security Cameras
- Power over Ethernet
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 (4)
Demonstration circuit 1145B, featuring the LTC4267, provides a complete IEEE 802.3af Powered Device (PD) interface and isolated 12V at 0.9A power supply solution for use in Power over Ethernet (PoE) applications. An optional connection is included for a 12V auxiliary supply on the secondary side that disables PoE when present.
Demonstration circuit 804 is a Power over Ethernet PD Interface with Integrated Switching Regulator featuring the LTC4267. It provides a complete IEEE 802.3af power device (PD) interface and isolated 3.3V power supply solution for use in Power over Ethernet (PoE) applications.
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.