What are the benefits of an electronic breaker with input overvoltage protection?

In the case of the power supply of the receiving device connected to the power supply terminal, in addition to protection by current limit due to failure of the load circuit, it may be necessary to protect from overvoltage due to ringing and surges that occur when connecting cables. Such cases can be easily realized by using the LT4363.

Current Limited High Voltage Surge Stopper LT4363

The LT4363 is easy to use because it has an N-channel MOSFET driver, similar to the LT1910 mentioned in the related information article "Automatically resettable electronic circuit breaker". In addition, products that can handle high temperatures from -40°C to 125°C are available, and can also be used in automotive products.

Below are the features and functional block diagram of the LT4363.

 　Features of the LT4363

- Over 80V surge withstand at 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 Threshold
- Low supply current in shutdown: 7μA
- Shutdown pin withstands voltages from –60V to 100V
- Adjustable fault timer
- Control N-channel MOSFET
- Retry Duty Cycle on Fault: <1%
(LT4363-2)
- 12-pin (4mm x 3mm) DFN package, 12-pin MSOP
package, or 16-pin SO package

Example circuit and results using LTspice

Below is an example circuit with the LT4363 using LTspice.

The clamp voltage during overvoltage input is set with a voltage dividing resistor so that the FB pin is 1.275V. Please refer to the datasheet for the clamp operation against overvoltage.

The retry interval can be set with the capacitor connected to the TMR pin. Also, overcurrent detection can be set with the R2 shunt resistor.

The UV pin sets a level that prohibits operation at low voltage.

The OV pin sets a level that prohibits retrying in the event of an overvoltage fault, but this is also effective in cases of overcurrent. When set to input voltage IN, automatic recovery by retry is prohibited, and when connected to GND, automatic recovery is always possible. will be

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