Switched-bus based resonant switched-capacitor converter architecture

A resonant switched-capacitor converter apparatus, the apparatus comprising:

• a first-stage comprising a switched-capacitor (SC) converter;
• and
• a second-stage comprising at least one multi-resonant switched-capacitor (SC) converter;
• wherein the second-stage is connected to the first-stage through at least one intermediate switching bus;
• and
• wherein said apparatus is a 4-to-1 resonant switched-capacitor converter comprising:
• wherein the first stage is configured with a 2-to-1 step down conversion ratio in which power is received and passed through parallel switches connected to a first capacitor, wherein on an output side of the first capacitor is another pair of parallel switches whose outputs are mid-converter outputs, mid1 and mid2;
• wherein the second stage comprises two phases of 2-to-1 step down converters, each receiving one of the mid-converter outputs to a second capacitor, an other end of which is coupled through a switch to ground;
• and
• wherein each output side connection of the second capacitor passes through a switch and then are connected to a common inductor having an output connected between the two phases of the second stage, and coupled to output capacitors for driving a load at the output of the 4-to-1 resonant switched-capacitor converter.