Generally, this disclosure describes an apparatus. The apparatus includes switch controller circuitry and zero crossing logic circuitry. The switch controller circuitry is to control a conduction state of a high side switch and a low side switch in a DC to DC converter. The zero crossing logic circuitry includes phase comparator circuitry, a first clocking circuitry and a second clocking circuitry. Each clocking circuitry includes one or more delay elements. The zero crossing logic circuitry is to monitor a switch node voltage, Vsw, and to determine whether Vsw is greater than a reference, Vref. The switch controller circuitry is to turn off a low side switch if Vsw is greater than Vref while the low side switch is turned on, Vsw greater than Vref corresponding to a negative inductor current.