Intelligent diagnostic features available for high side power switching

System fault mode considerations make high side switching desirable in many automotive applications. These switches must withstand 10 kV module level electro-static discharge and 60 V alternator load dump. An automotive high side switch (HSS) must control negative inductive flyback voltages during normal operation and during loss of battery. To control high current loads in the automotive environment, an HSS must also be able to operate with an ambient temperature up to 125°C. Motorola is in production with two dual output high side switches for the automotive industry. These high side switches provide real-time diagnostics while controlling up to four ampere loads at 105°C. This paper discusses the features available in this family of HSS ICs and their operation in automotive modules. Features addressed include: input control, overvoltage detection and protection, output on and off open load detection, output short detection, power switching capability, output current limiting and shutdown, output thermal detection and shutdown, dynamic output clamping, and packaging options. Application advantages, performance, and cost trade-offs of each feature are addressed