In a switching mode DC-to-DC power converter including a high-side transistor connected between an input voltage and an output node, a low-side transistor connected between the output node and a reference potential, and an inductor connected to the output node to derive an output voltage and an output current, a current sense apparatus and method employs a ramp signal generator to generate a ramp signal with a slope proportional to the difference between the input and output voltages, a DC signal generator to generate a DC signal proportional to the DC component of the current through the low-side transistor, and a summing circuit for combining the ramp and DC signals.