Differential hysteretic DC-DC converter

A method of operating a hysteretic DC-DC converter, the method comprising:

• comparing an output of a hysteretic DC-DC converter to a reference signal to generate a first difference signal;
• comparing a load ground to a reference signal ground to generate a second difference signal, the load ground being a ground reference of the output of the converter and the reference signal ground being a ground reference of the reference signal;
• generating a comparator output by adding together the first difference signal and the second difference signal;
• and
• providing the comparator output to a control circuit, the control circuit being configured to regulate the output of the converter based on the comparator output.

A hysteretic DC-DC converter comprising:

• a reference circuit configured to generate a reference voltage, the reference voltage having a reference signal ground as ground reference;
• a hysteretic comparator configured to compare a load ground and the reference signal ground to generate a first difference signal and to compare an output voltage of the converter and the reference voltage to generate a second difference signal, the hysteretic comparator being further configured to add together the first difference signal and the second difference signal to generate a comparator output, the load ground being a ground reference of the output voltage of the converter;
• and
• a control circuit configured to vary the output voltage of the converter based on the comparator output.