STEP-UP POWER-SUPPLY DEVICE AND INJECTOR-DRIVING SYSTEM

摘要

This invention reduces the size of a step-up power-supply device and an injector-driving system containing same. An inductor-current control unit (36) uses detection results from an inductor-current sensor (42) to control an inductor current (IL) by controlling a switching element (14). Said inductor-current control unit (36) is configured with: a first threshold set that contains a lower current threshold and an upper current threshold; and a second threshold set that contains a lower current threshold and an upper current threshold, both of which are higher than the first threshold set. The inductor-current control unit (36) controls the switching element (14) such that the inductor current (IL) falls between the lower and upper current thresholds of either the first threshold set or the second threshold set. The inductor-current control unit (36) switches between the first threshold set and the second threshold set so as to follow a load current generated in an inductor (17).