3A, 36V input, 1.4MHz — the parametric fit for a 12 V or 24 V rail
The LMR33630BRNXR is a Texas Instruments SIMPLE SWITCHER® step-down (buck) converter delivering 3 A continuous output from a 3.8 V to 36 V input rail. The adjustable output range from 1 V up to 24 V covers common intermediate bus voltages in industrial and automotive power chains. Switching at 1.4 MHz keeps the inductor and output capacitor physically small — a 4.7 µH to 10 µH inductor in a 1212 or 1210 footprint is typical — while the synchronous rectifier (integrated low-side FET) maintains efficiency above 90% across most of the load range.
Package and temperature grade for production assembly
Housed in a 12-VQFN-HR (3x2 mm) package with wettable flank terminals, the LMR33630BRNXR supports automated optical inspection (AOI) of the solder joints after reflow — a requirement in high-reliability and automotive-tier assembly lines. The operating junction temperature range of -40°C to 125°C covers both cold-crank and under-hood ambient conditions. Texas Instruments lists the part as Active and RoHS3 compliant, so no end-of-life or obsolescence risk for new designs. The SIMPLE SWITCHER® family includes Webench® design support files for inductor selection and loop compensation — the compensation network is internal, so the external BOM stays to the input/output caps, inductor, and feedback divider.