Features and Benefits
- Withstands Surges Over 80V with VCC Clamp
- Wide Operating Voltage Range: 4V to 80V
- Adjustable Output Clamp Voltage
- Fast Overcurrent Limit: Less Than 5μs
- Reverse Input Protection to –60V
- Adjustable UV/OV Comparator Thresholds
- Low 7μA Shutdown Current
- Shutdown Pin Withstands –60V to 100V
- Adjustable Fault Timer
- Controls N-Channel MOSFET
- Less Than 1% Retry Duty Cycle During Faults, LT4363-2
- Available in 12-Pin (4mm × 3mm) DFN, 12-Pin MSOP or 16-Pin SO Packages
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 LT4363-1 remains off until reset whereas the LT4363-2 restarts after a cool down period.
Two precision comparators can monitor the input supply for overvoltage (OV) and undervoltage (UV) conditions. When the potential is below the UV threshold, the external MOSFET is kept off. If the input supply voltage is above the OV threshold, the MOSFET is not allowed to turn back on. Back-to-back MOSFETs can be used in lieu of a Schottky diode for reverse input protection, reducing voltage drop and power loss. A shutdown pin reduces the quiescent current to less than 7μA during shutdown.
- Automotive/Avionic Surge Protection
- Hot Swap™/Live Insertion
- High Side Switch for Battery Powered Systems
- Intrinsic Safety Applications
Markets and Technologies
Product Lifecycle Recommended for New Designs
This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.
Evaluation Kits (5)
DC2062A-B: Demo Board for LT4363 High Voltage Surge Stopper with Current Limit.
Demonstration circuit 2150A uses the LTC4366-2 and LT4363-2 surge stoppers to satisfy MIL-STD-1275D. This specification, created by the United States Department of Defense, sets down requirements of electrical systems powered from a military vehicle’s 28V power supply. DC2150A’s output voltage is limited to 44V when faced with MIL-STD-1275D’s onerous surge, spike, and ripple conditions. In most circumstances, satisfying MIL-STD-1275D is as simple as placing this circuit in front of a 44V tolerant device. The default version, DC2150A-C, provides a minimum of 4A to the output in all conditions except the ±7V ripple condition (14Vpeak-to-peak). During the ripple condition, DC2150A-C provides a minimum of 2.8A to the load. Exceeding 2.8A during the input ripple condition may cause DC2150A-C to timeout and shutoff in less than MIL-STD-1275D’s one minute ripple ride-through requirement.
DC1935A-B: Demo Board for the LT4363 High Voltage Surge Stopper with Current Limit.
DC1935A-A: Demo Board for the LT4363 High Voltage Surge Stopper with Current Limit.
Tools & Simulations
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
To launch ready-to-run LTspice demonstration circuits for this part:
Step 1: Download and install LTspice on your computer.
Step 2: Click on the link in the section below to download a demonstration circuit.
Step 3: If LTspice does not automatically open after clicking the link below, you can instead run the simulation by right clicking on the link and selecting “Save Target As.” After saving the file to your computer, start LTspice and open the demonstration circuit by selecting ‘Open’ from the ‘File’ menu.
Models for the following parts are available in LTspice:
Technical Articles (2)
Rarely Asked Questions (1)
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