6A automotive buck-boost with wide input range
The Maxim MAX25239AFFB/VY+T is a single-output, synchronous buck-boost switching regulator rated for 6A continuous output current. It accepts a 2V to 36V input range, covering cold-crank at the low end and load-dump transients at the high end, with an adjustable output from 3V up to 6.5V (a fixed 5V option is also available). Switching at 400kHz, it uses synchronous rectification for efficiency across the operating range.
Package and thermal: rework notes for the 22-FC2QFN
Housed in a 22-PowerWFQFN (4.25x4.25 mm body, supplier package 22-FC2QFN), this is a QFN with an exposed thermal pad. The pad needs a via-stitched ground plane to pull heat out; without it the junction will run away above 4A continuous in a 85°C ambient. For rework: the small body and fine pitch mean a hot-air station with a nozzle that matches the part size, preheat the board to 100°C, and use a low-melt solder paste. The pad is the only thermal path — lift the part, not the pad, by working the corners first with flux. Orientation is marked by pin 1 chamfer on the top; confirm alignment under magnification before reflow.
The AEC-Q100 qualification (series Automotive, AEC-Q100) is the gate for tier-1 supplier BOMs.