Power-supply overvoltage protection circuit for motorcycle on-board electronics

A simple circuit used to protect on-board electronics from power-supply overvoltages due to the electrical environment of motorcycles is presented in this paper. The circuit is integrated as a macrocell to be embedded in the on-board electronics in order to protect it from dangerous voltage levels (up to 200 V) on the power-supply. This choice avoids the use of any external component except a resistor and a capacitor. The circuit behaves as a non-linearly driven shunt switch, which turns the supply voltage off when activated. Its main features are avoiding a large power consumption on the power MOS shunt and allowing a reduced area occupation of it. The paper describes the circuit, presents simulation results and finally the experimental characterization of the prototype chips fabricated with a 2 /spl mu/m CMOS high voltage (50 V) process.