Evaluation of Usage of Solid State MOSFET Switches in Test Equipment for SENT Automotive Sensors

The test equipment for automotive electronics industry is often used to assess the behavior of the ECUs (Electronic Control Units) in case of simulated faults. Since the sensors of electronic systems in a vehicle are placed in specific points of the car chassis, they must be interfaced with the electronic control units. For testing in a controlled environment (test laboratories) of these interfaces is needed to emulate the fault scenarios with the test equipment – short circuits, signal line interruptions, increased lines resistance, etc. A matrix of switches is able to cover most of the test scenarios. The more sensors and test scenarios, the more complex is the switch matrix. The development of solid-state switches based on field effect transistors in the last decades makes this switch type more attractive in this regard. Our research is focused on investigating the advantages and disadvantages of CMOS switches and MOSFET relays in automotive testing equipment, compared with electromechanical switches. Unlike electromechanical switches, the solid state MOSFET switches have no moving parts (no contact bouncing), and they are much smaller, which makes them attractive for compact systems and higher switching speed. At the same time, electrical parameters are more stable and predictable.