Airbag system

An airbag system comprising a first processing circuit for determining on a collision of a vehicle based on an output from a sensor for detecting a collision of the vehicle and a second processing circuit for outputting a signal to deploy an airbag based on an output from the first processing circuit, wherein

• the second processing circuit is made of one Application Specific Integrated Circuit, the second processing circuit comprising:
• a communication unit that controls information communication between the first processing circuit and an electronic control unit outside the airbag system;
• a first power supply unit that generates a first driving voltage for driving the first and second processing circuits based on a voltage of an outside power supply, the first power supply unit that includes backup power supply unit that supplies a backup voltage when the voltage of the outside power supply falls;
• a second power supply unit that supplies a second driving voltage to the communication unit based on an output of the first power supply unit;
• and
• a power supply control unit that stops the supply of the second driving voltage from the second power supply unit to the communication unit on detection of a fall in the voltage of the outside power supply.