Features and Benefits

  • High-Voltage Capability (72V) Allows Direct Monitoring, Ensuring Reliable System Operation in Automotive and Industrial Applications
    • Wide Supply Voltage Range (5.75V to 72V)
    • Specified from -40°C to +125°C
    • Adjustable DC-DC Input Undervoltage-Threshold Power-OK Output
    • Adjustable DC-DC Output Overvoltage Thresholds
  • Integrated Protection Features Improve System Reliability
    • Internal Charge Pump Ensures n-Channel MOSFET is Fully Enhanced During Normal Operation (VGS = 10V)
    • Fast GATE Shutoff During Overvoltage with 20mA Sink Capability
    • Latches Off External n-Channel MOSFET During High-Voltage Transients
    • Overtemperature-Shutdown Protection

Product Details

The MAX6399 is a small overvoltage and undervoltage protection circuit. The device can monitor a DC-DC output voltage and quickly disconnect the power source from the DC-DC input load when an overvoltage condition occurs. A power-OK output signals when the DC-DC input voltage falls below an adjustable threshold. This controller architecture provides the ability to size the external n-channel MOSFET to meet specific load current requirements.

When the DC-DC monitored output voltage is below the user-adjustable overvoltage threshold, the GATE output of the MAX6399 goes high to enhance the n-channel MOSFET. The MAX6399 offers internal charge-pump circuitry that allows the GATE voltage to be 10V above the input voltage (VGS = 10V) to fully enhance the external n-channel MOSFET, thus minimizing the drain-to- source resistance.

When the monitored output voltage rises above the user-adjusted overvoltage threshold, the GATE output rapidly pulls low to shut off the MOSFET. The MOSFET remains latched off until either the MAX6399 input power or SHDN-bar input is cycled. The MAX6399 includes a logic-low shutdown input that disables the GATE. An internal overtemperature detector also disables the gate when the MAX6399 temperature reaches the thermal-shutdown threshold.

The device operates over a wide supply voltage range (5.75V to 72V) and is offered in a small TDFN package, fully specified from -40°C to +125°C.


  • Networking
  • RAID
  • Server
  • Telecom

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.

Product Recommendations

MAX6399 Companion 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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