3 A buck in a 3x2 mm QFN — thermal and layout reality
The TPS628132DQWRWYRQ1 is a fixed-output 1.35 V step-down converter rated for 3 A continuous in a 9-VFQFN-HR (3x2 mm) package. Switching frequency spans 1.8 MHz to 4 MHz, which lets you shrink the inductor and output capacitor but pushes the switching node layout to the front of the board review. The synchronous rectifier is integrated, so no external Schottky is needed for the low-side path.
Input voltage range is 2.75 V to 6 V (min to max), so this part runs directly off a 3.3 V or 5 V rail without an intermediate regulator. The fixed 1.35 V output is set internally — no feedback divider resistors, which saves two components and one tolerance stack. Compared to the LM53625LQURNLRQ1 (2.5 A output, 2.1 MHz fixed frequency) or the LMR33630APCQRNXRQ1 (3 A adjustable output, 2.1 MHz fixed), the TPS628132DQWRWYRQ1 offers a wider switching-frequency range and a smaller package, at the cost of a fixed output voltage. If your rail needs to be adjustable, the LMR33630 is the closer sibling; if you need a fixed 1.35 V at 3 A in a tiny footprint, this is the one.
Active production — no LTB signal on this AEC-Q100 part
The AEC-Q100 qualification covers automotive-grade temperature and reliability — the same device serves under-hood and cabin-domain power rails. The 9-VFQFN package has wettable flanks, which improves solder-joint inspection for automotive production lines using AOI.