IGNITER SEMICONDUCTOR DEVICE, IGNITER SYSTEM, AND IGNITION COIL UNIT

The present invention provides an igniter semiconductor device 100 and an igniter system which can prevent the influence of a voltage drop of an ON signal voltage input to an input terminal 2 and the influence of a surge voltage, allow a switching element 5 to operate reliably, and prevent an ignition failure. An igniter semiconductor device 100 includes: an external terminal including at least an input terminal 2, an output terminal 3 electrically connected to an ignition coil, a ground terminal 4, and a power supply terminal 1 electrically connected to a regulated power supply wire outside the igniter semiconductor device 100; a switching element 5 for controlling current flowing in the ignition coil; and a driving circuit 7 that receives power through the power supply terminal 1 and drives the switching element 5 based on a signal input from the input terminal 2.