Surge protection prevents unwanted voltage pulses in the vehicle wiring from damaging sensitive subsystems such as safety systems, control modules and infotainment equipment. Pulses can be caused by events such as electrostatic discharges (ESD) from occupants, turn-on/off of subsystems such as motor drives or climate control, or load dumps when a significant load such as the battery is suddenly disconnected. Historically, designers have chosen from devices certified to industrial standards that specify pulse shapes unrepresentative of those expected in road vehicles.
ST’s SM4TY-SM30TY series of Transil miniature surge-protection devices - are certified to pulse specifications used by the automotive industry. They are also qualified to the AEC-Q101 automotive reliability test standard for discrete semiconductors, and have a full Automotive-Grade Approval Certificate (AGAC). This saves designers researching for equivalence between industrial and automotive standards, and then re-certifying each new subsystem design independently. Hence new innovations are able to reach the market quickly and cost efficiently.
The Transil protection devices are housed in miniature surface-mount power packages occupying from 12.8mm2 to 46mm2 of pc-board space, capable of handling from 400W to 3000W of power contained in pulses and ESD transients present on the vehicle wiring.