Features and Benefits

  • IEEE 802.3af/at Compliant
  • Up to 40W for Single-Port PSE Applications
  • Integrated 0.5Ω Power MOSFET and Sense Resistor
  • PD Detection and Classification
  • Programmable Current Limit for Class 5 PDs
  • High-Capacitance Detection for Legacy Devices
  • Supports Both DC and AC Load Removal Detections
  • Current Foldback and Duty Cycle-Controlled Current Limit
  • LED Indicator for Port Status
  • Direct Fast-Shutdown Control Capability
  • Space-Saving, 28-Pin TQFN (5mm x 5mm) Package

Product Details

The MAX5971A is a single-port, power-sourcing equipment (PSE) power controller designed for use in IEEE® 802.3af/at-compliant PSE. This device provides powered device (PD) discovery, classification, current limit, DC and AC load-disconnect detections. The MAX5971A operates automatically without the need for any software programming and features an integrated power MOSFET and sense resistor. The device also supports new Class 5 and 2-event classification for detection and classification of high-power PDs. The MAX5971A provides up to 40W to a single port (Class 5 enabled) and still provides high-capacitance detection for legacy PDs.

The MAX5971A provides input undervoltage lockout (UVLO), input overvoltage lockout, overtemperature detection, output voltage slew-rate limit during startup, and LED status indication.

The MAX5971A is available in a space-saving, 28-pin TQFN (5mm x 5mm) power package, and is rated for the extended (-40°C to +85°C) temperature range.


  • Industrial Automation Equipment
  • Single-Port PSE End-Point Applications
  • Single-Port PSE Power Injectors (Midspan Applications)
  • Switches/Routers
  • Wireless LAN Access Points/WiMAX™ Base Station

Product Lifecycle icon-recommended 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 (1)

Product Recommendations

MAX5971A Companion Parts

Recommended Related Parts

Design Resources

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.

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Evaluation Boards

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Up to two boards can be purchased through Analog.com. To order more than two, please purchase through one of our listed distributors.

Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.