Lower power controller for DC to DC converters

A method of controlling a DC to DC converter including an inductive storage element, a first switching element, and a second switching element, said method comprising:

• applying an input voltage to first and second input terminals of a converter circuit;
• generating an output voltage at first and second output terminals of said converter circuit, said second output terminal being connected to said second input terminal;
• closing a first switching element and opening a second switching element during a first operating phase;
• directing a first current through an inductive storage element to a first output terminal in the first operating phase;
• opening the first switching element and closing the second switching element during a second operating phase;
• directing the first current through the inductive storage element to said second input terminal in the second operating phase;
• charging a timing control capacitor during said second operating phase;
• comparing, during the second operating phase, a first voltage proportional to a voltage across the timing control capacitor to a first reference voltage, said first voltage increasing during said second operating phase;
• switching from the second operating phase to the first operating phase when the first voltage equals the first reference voltage;
• comparing, during the first operating phase, a second voltage proportional to the output voltage to a second reference voltage, said second voltage increasing during the first operating phase;
• and
• switching from the first operating phase to the second operating phase when the second voltage equals the second reference voltage.

A DC to DC converter comprising:

• a converter circuit for converting an input voltage at first and second input terminals to an output voltage at first and second output terminals, said second output terminal being connected to said second input terminal, said converter circuit comprising:
• an inductor connected between said first input terminal and the first output terminal;
• a first switching element configured to close during a first operating phase to direct a first current through the inductor to said first output terminal;
• a second switching element configured close during a second operating phase to direct the first current through the inductor to the second input terminal;
• a control circuit comprising:
• a timing control capacitor configured to charge during said second operating phase;
• a logic circuit configured to:
• compare, during the second operating phase, a first voltage proportional to a voltage across the timing control capacitor to a first reference voltage, said first voltage increasing during said second operating phase;
• close the first switching element and open the second switching element when the first voltage equals the first reference voltage to switch the converter circuit to the first operating phase;
• compare, during the first operating phase, a second voltage proportional to the output voltage to a second reference voltage;
• and
• close the second switching element and open the first switching element when the second voltage equals the second reference voltage to switch the converter circuit to the second operating phase.