Automotive buck regulator with 5.5 A continuous output
The LMS3655NQURNLRQ1 is a step-down buck regulator from Texas Instruments, part of the Automotive, AEC-Q100 series. It delivers a fixed 3.3 V output at up to 5.5 A continuous from a 3.9 V to 36 V input rail.
Input range and thermal envelope for under-hood duty
The 3.9 V minimum input lets it operate through a cold-crank event on a nominal 12 V battery, while the 36 V maximum covers load-dump transients without an external clamp. The -40°C to 150°C junction temperature range matches AEC-Q100 Grade 0 requirements — the part survives under-hood ambient temperatures where the engine bay sees 105°C on a summer grade. Switching frequency is fixed at 400 kHz, a practical midpoint that keeps the inductor small while staying below the AM broadcast band. The part does not include a synchronous rectifier — the external Schottky diode adds a predictable forward drop but avoids shoot-through concerns at high input voltage.
22-VQFN package with wettable flank for AOI
This is a practical advantage for automotive production lines where bottom-only terminations hide voids under the package.
Active production and sourcing posture
Pricing and lead time are confirmed at quote against the BOM quantity.