A DC-DC converter and corresponding method for transitioning between a discontinuous conduction mode, DCM, and a continuous conduction mode, CCM, wherein the DC-DC converter is configured to power a signal processing system within an integrated circuit, is provided. The method comprises receiving input data, wherein the input data is for inputting into the signal processing system; determining an amplitude of the input data; and transitioning between DCM and CCM based on the amplitude of the input data. A DC-DC converter and respective method for transitioning from CCM to DCM comprising determining an estimated current representative of an inductor current through an inductor of the DC-DC converter; and transitioning from CCM to DCM based on the estimated current, is provided. A DC-DC converter and respective method for transitioning from DCM to CCM comprising determining either an output voltage of the DC-DC converter or a duty cycle of the DC-DC converter; and transitioning from DCM to CCM based on the determined output voltage or duty cycle of the DC-DC converter, is provided.