Switching converter equipped with adaptive frequency control function

Abstract

A switching converter equipped with an adaptive frequency control function includes a switching unit, an inductor, an output capacitor, a zero crossing detector that receives a signal of the switching node and a signal of the output terminal, that are fed back, and detects whether or not an inductor current flowing through the inductor crosses a zero point, a DCM/CCM detector that outputs an operation section discrimination signal that discriminates a current operation section by dividing the current operation section into a discontinuous conduction mode (DCM) operation section and a continuous conduction mode (CCM) operation section according to a zero crossing detection signal output by the zero crossing detector, a variable oscillator that changes and outputs a clock frequency signal according to the operation section discrimination signal output by the DCM/CCM detector, and a controller that controls switching of switches constituting the switching unit according to the clock frequency signal output by the variable oscillator.