Abstract: Aspects of the invention are directed to an ignition semiconductor device that includes an output IGBT for ON-OFF control of a primary current in an ignition coil and a current control circuit for controlling a magnitude of the primary current in the ignition coil, the current control circuit being operated by the voltage between the gate terminal and the emitter terminal. The current control circuit can include a sense IGBT, a sense resistance, a gate resistance, a reference voltage, level shift circuits, a self shut down signal generator, a self shut down circuit, an operational amplifier, a MOSFET, a gate voltage control circuit , a pulse generation circuit, and a switching circuit. The self shut down signal generator, on detecting an abnormal state, can deliver a self shut down signal and the pulse generation circuit can generate a pulse signal to short-circuit the switching circuit.

Abstract: A controlled energy ignition system for an internal combustion engine includes an ignition coil having a primary coil and a secondary coil coupled to first and second electrodes of an ignition plug defining a spark gap therebetween, wherein the primary coil is responsive to activation of a control signal to produce a spark voltage across the secondary coil and across the spark gap. The secondary coil is responsive to the spark voltage to produce a discharge current across the spark gap of the ignition plug. In accordance with one aspect of the invention, means are provided to draw discharge current away from the ignition plug to thereby limit the discharge current to below a threshold current value within some predefined time period after activation of the control signal.