MAX4840:Overvoltage Protection Controllers with Status FLAG

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.

Key Features
  • 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
MAX4838, MAX4839, MAX4840, MAX4841: Typical Operating Circuit
MAX4838, MAX4839, MAX4840, MAX4841: Typical Operating Circuit
Applications/Uses
  • Cell Phones
  • Digital Still Cameras
  • MP3 Players
  • PDAs and Palmtop Devices
DataSheet
titleDownload file
MAX4838-MAX4842 Data SheetMAX4838-MAX4842.pdf
Parametrics
Part NumberChannelsVIN
(V)
VIN
(V)
Over Voltage Trip Level
(V)
Under Voltage Lockout
(V)
VGATE
(V)
Over Volt. FlagtGATE (On)
(ms)
tGATE (Off)
(µs)
Package/PinsBudgetary
Price
minmaxSee Notes
MAX483811.2287.43.2510Open-Drain106SC-70/6-
MAX48405.8Open-DrainSC-70/6$1.05 @1k
MAX48415.8Push-PullSC-70/6$1.05 @1k
Ordering Information
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX4840EXT+ActiveSC-70,;6 pin;5.3 mm²-40°C to +85°CLead Free
MAX4840EXT+TActiveSC-70,;6 pin;5.3 mm²-40°C to +85°CLead Free
MAX4840EXT-TNo Longer AvailableMAX4840EXT+TSC-70,;6 pin;5.3 mm²-40°C to +85°CNo
MAX4838-MAX4842.pdf MAX4841
MAX4838-MAX4842.pdf MAX4842