Nonlinear control loop for DC-DC converters

A nonlinear converter, such as a DC-DC converter, includes a nonlinear controller configured to receive an output voltage and a current, and configured to generate a PWM signal. The PWM signal is generated based on setting the converter to a first phase associated with both buck and boost modes when a clock signal is asserted, and selecting a second phase associated with the buck mode of the converter, if a sliding function signal achieves a first predetermined relationship with respect to a buck threshold before a next clock signal is asserted, or selecting a third phase associated with the boost mode of the converter, if the sliding function signal achieves a second predetermined relationship with respect to a boost threshold before a next clock signal is asserted. The nonlinear converter may include a power stage configured to provide the output voltage and a coil current to the nonlinear controller.