This master's thesis explains theoretical operation, schematic design, production and testing of bidirectional mosfet load switch, implemented for protecting system's with two voltage levels.
In the beggining, the topology of the system is presented with emphasis on different connection configurations of the DC/DC converter. As a consequence of a different topology, there is a lower current running through the GND link, therefore we have decided to locate a load switch to this link.
A big part of the thesis is describing the board design in Altium. Each part of the board is presented apart from each other in a logical flow. The board had to fulfil the folowing functions: overvoltage protection, undervoltage protection, bidirectional overcurrent protection and soft start of highly capacitive loads. From other system's on the market our system differs with the location of the load switch and a more complicated approach to soft starting of capacitive loads and is unable to work with only an high voltage source present.
At the end of this document, the results of the functionality testing are presented, to prove that the system works as intended.