4A in a 2×3 mm VQFN — the footprint trade
The TPS62136RGXT is a 4A step-down buck converter from Texas Instruments, in an 11-VFQFN-HR package that measures 2×3 mm on the board. Output is adjustable from 0.8V up to 12V, with a fixed 1 MHz switching frequency that lets you use small-value inductors and ceramic output caps. The synchronous rectifier is integrated — no external Schottky needed, which saves one component and one solder joint per board.
Input range and thermal envelope
Input voltage spans 3V to 17V, so it runs from a 5V rail or a 12V rail without a pre-regulator. The 4A output at high ambient needs the exposed pad soldered to a decent copper pour — the 2×3 mm package has limited thermal mass, so the board copper does the heat spreading.