1. Products
  2. Power Monitor, Control, and Protection
  3. Surge Stopper, Overvoltage, and Overcurrent Protection
  4. MAX4840A


Features and Benefits

  • Overvoltage Protection Up to +28V
  • Preset 7.4V or 5.8V Overvoltage Trip Level
  • Drives 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 and µDFN packages
  • Lead-Free

Product Details

The MAX4838A/MAX4840A/MAX4842A 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 MAX4838A/MAX4840A/MAX4842A 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 MAX4838A has a 7.4V overvoltage threshold, and the MAX4840A has a 5.8V overvoltage threshold. The MAX4842A has a 4.7V overvoltage threshold. The MAX4838A/MAX4840A have an undervoltage lockout (UVLO) threshold of 3.25V while the MAX4842A has a UVLO of 2.5V. 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 MAX4838A/MAX4840A/MAX4842A have an open-drain active-low FLAG output. Active-low FLAG output asserts immediately to an overvoltage fault.

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

All devices are offered in a small 6-pin SC70 package and 6-pin 1.5mm x 1.0mm µDFN packages and are specified over the extended temperature range of -40°C to +85°C.


  • Cell Phones
  • Digital Still Cameras
  • 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.

Product Recommendations

MAX4840A 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.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
MAX4840AEXT+ Material Declaration Reliability Data Single Chip Package
MAX4840AEXT+T Material Declaration Reliability Data Single Chip Package
Wafer Fabrication Data MAX4840A Reliability Data

Sample & Buy

Ordering FAQs

See our Ordering FAQs for answers to questions about online orders, payment options and more.


Buy Now Pricing

(**) Displayed Buy Now Price and Price Range is based on small quantity orders.


List Pricing

(*)The 1Ku list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.


Lead Times

Please see the latest communication from our CCO regarding lead times.



Selecting the Sample button above will redirect to the third-party ADI Sample Site. The part selected will carry over to your cart on this site once logged in. Please create a new account there if you have never used the site before. Contact SampleSupport@analog.com with any questions regarding this Sample Site.

Price Table Help