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Overvoltage-Protection Controllers with Status Flag

Prevent Damage to Electronic Components if a Wrong Adapter Is Plugged In

Product Details

Key Features

Simplified Block Diagram

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Key Features

  • 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

Applications/Uses

  • Cell Phones
  • Digital Still Cameras
  • MP3 Players
  • PDAs and Palmtop Devices

Description

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.

Simplified Block Diagram

MAX4838A, MAX4840A, MAX4842A: Typical Operating Circuit MAX4838A, MAX4840A, MAX4842A: Typical Operating Circuit Zoom icon

Technical Docs

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal .