Patent ID: 7341052

Claim:
A power switching control device comprising: a switching IC including a semiconductor power switching element, which turns on and off supply of coil current to an ignition coil, the switching IC including a temperature sensor constructed with at least one diode for detecting temperature of the switching IC; a control circuit IC provided in a chip form separate from the switching IC for outputting a control signal to turn on and off the switching element, the control circuit IC generating the control signal in response to an ignition signal applied thereto, the control circuit IC including an overheat detector circuit for detecting an overheating of the switching IC based on a detection result of the temperature sensor and controlling the control signal to stop an operation of the switching element upon detection of the overheating; a bonding wire connecting the temperature sensor and the overheat detector circuit; a grounding terminal grounding the switching element and the temperature sensor, the grounding terminal further grounding the overheat detector circuit through the bonding wire and the switching IC; and a conductive layer provided between the control circuit IC and the grounding terminal to join the control circuit IC to the grounding terminal.