Zero-voltage switching hybrid switched-capacitor converter

A method of operating a voltage converter circuit, the method comprising:

• charging a first inductor of a switching converter circuit of the voltage converter circuit and a second inductor of the voltage converter circuit using energy provided by a charge pump circuit of the voltage converter circuit, the charge pump circuit including at least four switch circuits connected in series, a flying capacitor coupled to a series connection between a first switch and a second switch of the at least four switch circuits, and a mid-point capacitor coupled directly to circuit ground, wherein the first inductor is coupled to a junction between a third switch circuit and a fourth switch circuit of the at least four switch circuits, and wherein the second inductor includes a first terminal coupled to a series connection of the at least four switch circuits, and a second terminal coupled in series to the mid-point capacitor;
• activating the at least four switch circuits in a specified sequence to generate a regulated, voltage at an output node of the voltage converter circuit, the specified sequence including turning on the third switch circuit after turning off the second and fourth switch circuits and a drain to source voltage of the third switch circuit is zero volts, and turn on the first switch circuit after the third switch circuit is turned on;
• and
• turning on the fourth switch circuit after turning off the first and third switch circuits and a drain to source voltage of the fourth switch circuit is zero volts, and turn on the second switch circuit after the fourth switch circuit is turned on.

A supply circuit comprising:

• a charge pump circuit including at least four switch circuits connected in series, a midpoint capacitor coupled directly to circuit ground, and a flying capacitor coupled to a series connection between a first switch circuit and a second switch circuit of the at least four switch circuits;
• a step-down switching converter circuit including a first inductor coupled to an output node of the supply circuit and coupled to a junction between a third switch circuit and a fourth switch circuit of the at least four switch circuits;
• a second inductor including a first terminal coupled directly in series with the flying capacitor and a second terminal coupled to a second series connection of the at least four switch circuits;
• a control circuit configured to turn on the third switch circuit after turning off the second and fourth switch circuits and a drain to source voltage of the third switch circuit is zero volts, and turn on the first switch circuit after the third switch circuit is turned on;
• and
• turn on the fourth switch circuit after turning off the first and third switch circuits and a drain to source voltage of the fourth switch circuit is zero volts, and turn on the second switch circuit after the fourth switch circuit is turned on.