SWITCHING CONTROL CIRCUIT

摘要

A switching control circuit for controlling the on/off operations of first and second series-connected transistors of a DC/DC converter in which the first and second transistors are turned on and off in a complementary manner so as to generate, from an input voltage applied to the first transistor, an output voltage having a target level. The switching control circuit comprises an error amplifying circuit that provides an error voltage obtained by amplifying an error between a feedback voltage in accordance with the output voltage and a lower one of a first reference voltage increasing with time and a second reference voltage serving as a reference of the target level; a comparing circuit that provides a signal of comparison between the feedback voltage and the error voltage provided by the error amplifying circuit; and a drive circuit that provides first and second control signals for controlling the first and second transistors, respectively, to turn, based on the comparison signal from the comparing circuit, the first and second transistors on and off in the complementary manner to provide the output voltage having the target level after the error voltage exceeds the feedback voltage.