MAX5945 Datasheet | Maxim Integrated

Features - IEEE 802.3af pliant - Pin and Function patible with LTC4259A - Controls Four Independent, -48V-Powered Ethernet Ports in Either Endpoint or Midspan PSE Applications - Wide Digital Power Input, VDIG, mon-Mode Range: VEE to (AGND + 7.7V) - PD Violation of Class Current Protection - PD Detection and Classification - Provides Both DC and AC Load Removal Detections - I2C-patible, 3-Wire Serial Interface - Fully Programmable and Configurable Operation Through I2C Interface - Current Foldback and Duty-Cycle Controlled/Programmable Current Limit - Short-Circuit Protection with Fast Gate Pulldown - Direct Fast Shutdown Control Capability - Programmable Direct Interrupt Output - Watchdog Mode Enable Hardware Graceful Takeover General Description The MAX5945 quad network power controller is designed for use in IEEE 802.3af-pliant power-sourcing equipment (PSE). The device provides power devices (PD) discovery, classification, current-limit, and both DC and AC load disconnect detections. The MAX5945 can be used in either endpoint PSE (LAN switches/routers) or midspan PSE (power injector) applications. The MAX5945 is pin and function patible with LTC4259A. The MAX5945 can operate autonomously or be controlled by software through an I2C- -patible interface. Separate input and output data lines (SDAIN and SDAOUT) allow usage with optocouplers. The MAX5945 is a slave device. Its four address inputs allow 16 unique MAX5945 addresses. A separate INT output and four independent shutdown inputs (SHD_) allow fast response from a fault to port shutdown. A RESET input allows hardware reset of the device. A special watchdog feature allows the hardware to gracefully take over control if the software crashes. A cadence timing feature allows the MAX5945 to be used in midspan systems. The MAX5945 is fully software configurable and programmable. A class-overcurrent detection function enables system power management to detect if a PD draws more current than the allowable amount for...