In 
Alvaro Aguilar makes a very nice pictorial explanation of how this 3-level buck converter works.
Mr. Aguilar's explanation shows two high-side mosfets, and two low-side mosfets, with flying cap.
In the BQ24725A charger (
) page 28 Figure 18 is the typical application, with two mosfet external switches.
Can you recommend a similar video to Mr. Aguilar's explanation, or some technical literature document that explains this stacked mosfet topology, where the VIN presents on the high side mosfet, at the common point of two mosfets is an inductor/cap, and the lower mosfet is driven to ground?
I see this topology in all kinds of dc-dc buck converters, yet I have found no document explaining this particular arrangement.
Thanks in advance.
