DC1935A-B

LINEAR TECHNOLOGY DC1935A-B Evaluation Board, High Voltage Surge Stopper, LT4363-2

is a demonstration circuit for the LT4363-2 surge stopper in a 12V, 2A application with auto retry version. The LT4363 surge stopper protects loads from high voltage transients. It regulates the output during an overvoltage event, such as load dump in vehicles, by controlling the gate of an external N-channel MOSFET. The output is limited to a safe value allowing the loads to continue functioning. The LT4363 also monitors the voltage drop between the SNS and OUT pins to protect against overcurrent faults. An internal amplifier limits the voltage across the current sense resistor to 50mV. In either fault condition, a timer is started inversely proportional to MOSFET stress. Before the timer expires, the FLT pin pulls low to warn of an impending power down. If the condition persists, the MOSFET is turned off. The LT4363-2 restarts after a cool down period.

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Withstands surges over 80V with Vcc clamp

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Wide operating voltage range of 4V to 80V

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Adjustable output clamp voltage

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Fast overcurrent limit

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Reverse input protection to -60V

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Adjustable UV/OV comparator thresholds

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Low 7uA shutdown current

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Shutdown pin withstands -60V to 100V

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Adjustable fault timer

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Less than 1% retry duty cycle during faults