US Patent 10404175 Converter topology with adaptive power path architecture

In described examples, a DC-DC converter provides electrical power. In response to an input voltage falling below a high voltage operation threshold, the converter repeatedly performs a first normal (N) phase and a second N phase. The first N phase includes delivering power through an inductor from the input voltage. The second N phase includes coupling an input terminal of the inductor to a ground. In response to the input voltage rising above a normal operation threshold, the converter performs a first high voltage (HV) phase, then a second HV phase, then a third HV phase, then the second HV phase, and then repeats from the first HV phase. The first HV phase includes delivering power through the inductor from the input voltage and charging a flying capacitor. The second HV phase includes coupling the input terminal of the inductor to the ground. The third HV phase includes delivering power through the inductor by discharging the flying capacitor through the inductor.