LTC4258 Datasheet | Linear Technology

.. Quad IEEE 802.3af Power over Ethernet Controller with Integrated Detection Features DESCRIPTIO - Controls Four Independent - 48V Powered Ethernet Ports - Each Port Includes: - IEEE 802®.3af pliant PD Detection and Classification - Output Current Limit with Foldback - Short-Circuit Protection with Fast Gate Pull-Down - PD Disconnect Using DC Sensing - Power Good Indication - Operates Autonomously or by I2CTM Control - 4-Bit Programmable Digital Address Allows Control of Up to 64 Ports - Programmable INT Pin Eliminates Software Polling - Current and Duty Cycle Limits Protect External FETs - Available in a 36-Pin SSOP Package U APPLICATIO S - IEEE 802.3af pliant Endpoint and Midspan Power Sources - IP Phone Systems - DTE Power Distribution , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. Hot Swap is a registered trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. The LTC®4258 is a quad - 48V Hot Swap TM controller designed for use in IEEE 802.3af pliant Power Sourcing Equipment (PSE). It consists of four independent ports, each with output current limit, short-circuit protection, plete Powered Device (PD) detection and classification capability, and programmable PD disconnect using DC sensing. Used with power MOSFETs and passives as in Figure 1, the LTC4258 can implement a plete IEEE 802.3af-pliant PSE. The LTC4258 can operate autonomously or be controlled by an I2C serial interface. Up to 16 LTC4258s may coexist on the same data bus, allowing up to 64 powered Ethernet ports to be controlled with only two digital lines. Fault conditions are optionally signaled with the INT pin to eliminate software polling. External power MOSFETs, current sense resistors and diodes allow easy scaling of current and power dissipation levels and provide protection against voltage and current spikes and ESD events. The LTC4258 is available in a...