High-Voltage, Overvoltage/Undervoltage, Protection Switch Controller
The MAX6399 is a small overvoltage and undervoltage protection circuit. The device can monitor a DC-DC output voltage and quickly disconnect the power source from the DC-DC input load when an overvoltage condition occurs. A power-OK output signals when the DC-DC input voltage falls below an adjustable threshold. This controller architecture provides the ability to size the external n-channel MOSFET to meet specific load current requirements.
When the DC-DC monitored output voltage is below the user-adjustable overvoltage threshold, the GATE output of the MAX6399 goes high to enhance the n-channel MOSFET. The MAX6399 offers internal charge-pump circuitry that allows the GATE voltage to be 10V above the input voltage (VGS = 10V) to fully enhance the external n-channel MOSFET, thus minimizing the drain-to- source resistance.
When the monitored output voltage rises above the user-adjusted overvoltage threshold, the GATE output rapidly pulls low to shut off the MOSFET. The MOSFET remains latched off until either the MAX6399 input power or SHDN-bar input is cycled. The MAX6399 includes a logic-low shutdown input that disables the GATE. An internal overtemperature detector also disables the gate when the MAX6399 temperature reaches the thermal-shutdown threshold.
The device operates over a wide supply voltage range (5.75V to 72V) and is offered in a small TDFN package, fully specified from -40°C to +125°C.
- High-Voltage Capability (72V) Allows Direct Monitoring, Ensuring Reliable System Operation in Automotive and Industrial Applications
- Wide Supply Voltage Range (5.75V to 72V)
- Specified from -40°C to +125°C
- Adjustable DC-DC Input Undervoltage-Threshold Power-OK Output
- Adjustable DC-DC Output Overvoltage Thresholds
- Integrated Protection Features Improve System Reliability
- Internal Charge Pump Ensures n-Channel MOSFET is Fully Enhanced During Normal Operation (VGS = 10V)
- Fast GATE Shutoff During Overvoltage with 20mA Sink Capability
- Latches Off External n-Channel MOSFET During High-Voltage Transients
- Overtemperature-Shutdown Protection
|Part Number||Reset Thresh.|
|Reset Out||tRESET||Watchdog Feature||Supervisor Features||Reset Thresh. Accur.|
|(min)||(@ +25°C)||(max)||(See Notes)|
|Device||Fab Process||Technology||Sample size||Rejects||FIT at 25°C||FIT at 55°C||Material Composition|