Automotive buck regulator for 12V/24V rails
The Texas Instruments LMS3635MQURNLRQ1 is a synchronous step-down (buck) regulator rated for 3.5A continuous output, built on the Automotive, AEC-Q100 platform. It accepts a 3.9V to 36V input range, covering nominal 12V and 24V automotive buses with headroom for load-dump transients. The adjustable output version lets you set the rail anywhere between a 3.3V minimum and 10V maximum, making it a single-device solution for ECU sub-rails, sensor supplies, and infotainment power trees.
Switching at 2.1 MHz — inductor size and EMI
The 2.1MHz switching frequency lets you use a physically smaller inductor (typically 2.2 µH to 4.7 µH range) compared to 400 kHz parts, which matters when board space is tight inside a 22-VQFN footprint. The synchronous rectifier improves efficiency at moderate loads and eliminates the external Schottky diode. At this frequency, layout discipline on the switch node is critical — keep the loop from the input cap through the IC to the inductor short.
Temperature range and package
The 22-VQFN-HR (5x4 mm) package with wettable flank enables automated optical inspection (AOI) of the solder joints, a requirement in automotive production lines.
Active lifecycle — no LTB concern
For production programs that need multi-year supply assurance, this part carries no imminent obsolescence risk.