Solution The In-Vehicle Computer Power Subsystem Challenges The challenging electrical and environment conditions found in modern automobile have a strong impact on the design of automotive power electronic equipment. Important factors affecting the design of electronics for this application include static and transient voltage ranges, electromagnetic interference and compatibility requirements (EMI/EMC). With the extensive use of computer in today's vehicles, protection from transient over voltages is essential to ensure reliable operation Typical Automotive Transients The transients on the automobile power supply range form the severe, high energy, transients generated by the alternator/regulator system to the low-level "noise" generated by the ignition system and various accessories. A standard automotive electrical system has all of these elements necessary to generate undesirable transients. The Society of Automotive Engineers (SAE) has defined the automotive power supply transients which are present in the system. With the extensive use of computer in today's vehicles, protection from transient over voltages is essential to ensure reliable operation. Acrosser Solution Nominal 14V 120V Lond Dum 6V Crank All in-vehicle computer power subsystem is designed with protections to prevent damage from most of the transient over voltage in vehicles. 1. Automotive Transient Voltage Suppression 2. Power On Delay to Skip Cold Crank 3. Over Voltage and Under Voltage Protection 4. Over Current Protection 5. Reverse Voltage Protection 6. Automotive Fuse 24V Jump Start Reverse Batterry Acrosser ensure its In-Vehicle Computers perform as designed during and after exposure to disturbance by certified with the E-Mark. E/e-Mark is the Economic Commission of Europe (ECE) that grants certificates to ensure all automobiles equipments sold by manufacturers meet traffic safety and environmental protection requirements. The E-Mark certification includes a series of vehicle transient voltage test according to the ISO 7637-2. ISO 7637-2 was prepared by Technical Committee ISO/TC 22, Road vehicles. It defined specifies bench tests for testing the compatibility to conducted electrical transients of equipment installed on passenger cars and light commercial vehicles fitted with a 12V electrical system or commercial vehicles