Internal combustion engine controller

Abstract

At the time of drop of an injector current of an internal combustion engine controller, the drop is performed quickly while heat generation of a drive circuit is suppressed, and valve closing response speed of the injector is enhanced. The internal combustion engine controller includes a drive circuit which drives an injector current, and a boost circuit which boosts a battery voltage, and includes a peak current path for guiding a boost voltage of the boost circuit to an upstream side of the injector via a boost side switching element and a boost side protection diode, a holding current path for guiding the battery voltage to the upstream side of the injector via a battery side switching element and a battery side protection diode, a ground current path which is connected to a power supply ground from a downstream side of the injector via a downstream side switching element, and a regenerating circuit which allows the boost circuit to regenerate electric energy of the injector from the downstream side of the injector via a current regenerating diode, wherein the regenerating path is provided with a voltage regulating section in series with the current regenerating diode, and the drive circuit controls drive of the switching element.