MAX4840AEXT+T

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. FLAG is held low for an additional 50ms after GATE goes high before deasserting. The MAX4838A/MAX4840A/MAX4842A have an open-drain FLAG output. The 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 (EN) to turn off the device. All devices are offered in a small 6-pin SC70 and 6-pin 1.5mm x 1.0mm µDFN packages and are specified over the -40℃ to +85℃ extended temperature range.

Applications

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

Key features

• Overvoltage Protection Up to +28V
• Preset 7.4V, 5.8V, or 4.7V Overvoltage Trip Level
• Drives Low-Cost nMOS FET
• Internal 50ms Startup Delay
• Internal Charge Pump
• Undervoltage Lockout
• ±15kV ESD-Protected Input
• Voltage Fault FLAG Indicator
• 6-Pin SC70 and µDFN Packages
• Lead Free