1. Products
  2. Power Monitor, Control, and Protection
  3. Surge Stopper, Overvoltage, and Overcurrent Protection
  4. MAX4840


Features and Benefits

  • Overvoltage Protection Up to 28V
  • Preset 7.4V, 5.8V, or 4.7V Overvoltage Trip Level
  • Drive Low-Cost NMOS FET
  • Internal 50ms Startup Delay
  • Internal Charge Pump
  • Undervoltage Lockout
  • 15kV ESD-Protected Input
  • Voltage Fault active-low FLAG Indicator
  • 6-Pin SC70 Package

Product Details

The MAX4838–MAX4842 are overvoltage protection ICs that protect low-voltage systems against voltages of up to 28V. If the input voltage exceeds the overvoltage trip level, the MAX4838–MAX4842 turn off the low-cost external n-channel FET(s) to prevent damage to the protected components. An internal charge pump eliminates the need for external capacitors and drives the FET gate for a simple, robust solution.

The MAX4838/MAX4839 have a 7.4V overvoltage threshold, and the MAX4840/MAX4841 have a 5.8V overvoltage threshold. The MAX4842 has a 4.7V overvoltage threshold. The MAX4838–MAX4841 have an undervoltage lockout (UVLO) threshold of 3.25V while the MAX4842 has a UVLO of 3.0V. In addition to the single FET configuration, the devices can be configured with back-to-back external FETs to prevent currents from being back-driven into the adapter.

On power-up, the device waits for 50ms before driving GATE high. Active-low FLAG is held low for an additional 50ms after GATE goes high before deasserting. The MAX4838/MAX4840/MAX4842 have an open-drain active-low FLAG output, and the MAX4839/MAX4841 have a pushpull FLAG output. The active-low FLAG output asserts immediately to an overvoltage fault.

Additional features include a 15kV ESD-protected input (when bypassed with a 1µF capacitor) and a shutdown pin (active-low EN) to turn off the device (MAX4838/MAX4840/MAX4842).

All devices are offered in a small 6-pin SC70 package and are specified for operation from -40°C to +85°C.


  • Cell Phones
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  • MP3 Players
  • PDAs and Palmtop Devices

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.

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.View our quality and reliability program and certifications for more information.

Part Number Material Declaration Reliability Data Pin/Package Drawing CAD Symbols, Footprints & 3D Models
MAX4840EXT+ Material Declaration Reliability Data Single Chip Package
MAX4840EXT+T Material Declaration Reliability Data Single Chip Package
Wafer Fabrication Data

Sample & Buy

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