Maxim MAX5971B single-port power-sourcing equipment controller

Maxim has introduced the MAX5971B, a single-port power-sourcing equipment controller for IEEE 802.3af/at-compliant, high-power power-over-ethernet applications.

The device integrates a 0.5 Ω power MOSFET, sense resistor and current monitor to save space and cost in PSE systems - the typical application circuit requires fewer than eight external components.

Additionally, it includes a 9-bit ADC and I²C interface to enable power management and power budgeting. Capable of delivering up to 40 W/port for PoE+ powered devices, the controller is suitable for IP phones, IP cameras, wireless LAN access points and video surveillance cameras.

This PSE controller is fully compliant to the IEEE 802.3af and IEEE 802.3at standards. The device operates from 32 to 60 V and provides IEEE 802.3af/at-compliant PD discovery, classification and DC/AC load-disconnect detection.

Class 5 and two-event classification are supported for detection and classification of high-power PDs and it also detects legacy (non-compliant) PDs that use high capacitance as the discovery signature.

The device is fully software configurable through its I²C-compatible, 2-wire serial interface. It can be controlled with a system microcontroller and can be configured to operate autonomously without the need for a host microcontroller or software. It can also be configured to operate in manual or semi-automatic modes.

Other device features include input undervoltage-lockout detection, input overvoltage detection, LED-status indication, overtemperature protection and output voltage slew-rate limiting during start-up.