A system includes a first switch connected to a voltage input and a switching node. A second switch is connected to the switching node and a reference potential. A first circuit generates first rising edges and first falling edges by comparing a voltage at the switching node to a first voltage reference. The first voltage reference is between the reference potential and the voltage input. A second circuit generates second rising edges and second falling edges by comparing the switching node voltage to a second voltage reference. The second voltage reference is less than the reference potential. The controller calculates delay times based on the first rising edges, the first falling edges, the second rising edges and the second falling edges. The controller generates drive signals for the first switch and the second switch based on a duty cycle and the delay times.