Why automotive electronic systems need Load Dump protection? "Load Dump" means the voltage irregular rise or down suddenly in short time, which is often occurring in complex automotive environment. When the devices consuming large power, for examples. electric windows, motors switch on/off, or power off in car, and short circuit, it will occur sudden surge. The automotive electronic products are quite sensitive with surge damage, especially for precise devices, audio systems and driving electronic computers. These products are used a number of microelectronic components which are easily destroyed by load dump. Therefore, how to protect these precise electronic products away from surge damage becomes a very important issue.