Differential sensing and maintenance of flying capacitor voltage in a switched-mode power supply circuit

A method for regulating power, comprising:

• operating a power supply circuit comprising:
• a first transistor;
• a second transistor coupled to the first transistor via a first node;
• a third transistor coupled to the second transistor via a second node;
• a fourth transistor coupled to the third transistor via a third node;
• and
• a first capacitive element having a first terminal coupled to the first node and having a second terminal coupled to the third node;
• and
• maintaining a defined voltage across the first capacitive element with a voltage control circuit coupled to the first capacitive element.

A power supply circuit comprising:

• a three-level buck converter circuit having:
• a plurality of transistors coupled between a power supply rail and a reference potential node;
• an inductive element coupled between the plurality of transistors and a load;
• and
• a capacitive element coupled to the plurality of transistors;
• and
• a voltage control circuit coupled to the capacitive element and configured to maintain a defined voltage across the capacitive element.

A power supply circuit comprising:

• a first transistor;
• a second transistor coupled to the first transistor via a first node;
• a third transistor coupled to the second transistor via a second node;
• a fourth transistor coupled to the third transistor via a third node;
• a first capacitive element having a first terminal coupled to the first node and having a second terminal coupled to the third node;
• and
• a switched-capacitor circuit coupled to the first capacitive element and configured to sense a differential voltage across the first capacitive element.