As the cost of gasoline rises and environmental concerns about vehicle exhaust attracts more and more attention, the auto industry is accelerating research on development of new power-train systems with less fuel consumption, higher power density, and enhanced robustness. Being an important part of the power-train system, the ignition system contributes significantly to the system’s efficiency, exhaust pollution reduction, and robustness.
Thanks to the development of high-voltage high-current power switches by the semiconductor industry, the vulnerable mechanical switches have been replaced by more reliable, high-power semiconductor devices. By using dual tower coils, the distributor can be removed. Using “on plug” type coils, the high-voltage connection wires can be eliminated. The most recent technology trends are integrating the ignition Insulated-Gate Bipolar Transistor (IGBT) into the ignition coil and integrating the IGBT’s control IC with diagnosis and protection functions into the single igniter module to make a more compact and simple ignition system.
Devices with high clamping voltages and high energy density handling capability (in most cases IGBTs), are desirable as increasing demand for better Miles-Per-Gallon (MPG) engines operating at higher compression ratios need higher sparking voltage and more energy to ignite a lean air- and-fuel mixture.
