Undervoltage and Reverse Supply Protection Controller

This is a High Voltage Undervoltage (UV), Overvoltage (OV) and Reverse Supply Protection Controller consists of LTC4365 chip and MOSFET. The controller protects the load circuit from input voltages that may be too high, too low or negative. It operates by controlling the gates of two back-back connected MOSFETs to keep the output in safe range. The OV and UV protection levels are adjusted by resistive dividers at the OV and UV pins. Asserting the SHDN pin disables the MOSFETs and places the LTC4365 in a low-current shutdown state. The FAULT pin is asserted when the controller is in shutdown mode or when the input voltage is outside of the UV or OV level.  The LTC4365 can withstand DC voltages between -40V and 60V and has a valid operating range 2.4V to 35V. In this project the circuit is optimized for 12V DC, Undervoltage is set to 5V DC and Overvoltage is 18V DC.