Maxim MAX5941BCSE+

Overview

The MAX5941A/MAX5941BCSE integrate a complete power IC for powered devices (PD) in a power-over-ethernet (PoE) system. The MAX5941A/MAX5941BCSE provide a PD interface and a compact DC-DC PWM controller suitable for flyback and forward converters in either isolated or nonisolated designs. The MAX5941A/MAX5941BCSE PD interface complies with the IEEE 802.3af standard, providing the PD with a detection signature, a classification signature, and an integrated isolation switch with programmable inrush current control. These devices also feature power-mode undervoltage lockout (UVLO) with wide hysteresis and power-good status outputs. The MAX5941A/MAX5941BCSE also integrate all the building blocks necessary for implementing DC-DC fixed-frequency isolated power supplies. These devices are a current-mode controller with an integrated high startup circuit suitable for isolated telecom/industrial voltage-range power supplies. A high-voltage startup circuit allows the PWM controller to draw power directly from the 18V to 67V input supply during startup. The switching frequency is internally trimmed to 275kHz ±10%, thus reducing magnetics and filter components. The MAX5941A allows an 85% operating duty cycle and can be used to implement flyback converters. The MAX5941BCSE limits the operating duty cycle to less than 50% and can be used in single-ended forward converters. The MAX5941A/MAX5941BCSE are designed to work with or without an external diode bridge in front of the PD. The MAX5941A/MAX5941BCSE are available in 16-pin SO packages.

Features

Applications

• Internet Appliances
• POS Terminals
• IEEE 802.3af Compliant PoE Powered Devices
• Non-Compliant, Application Specific Devices
• Higher Power Ethernet Powered Devices
• IP Phone Power Management
• Wireless Access Points
• Security Cameras
• Power over Ethernet
• PoE powered device appliances