Automotive-grade buck/boost with a 1.5A switch
The MC33063AQDRQ1 is a Texas Instruments switching regulator from the Automotive, AEC-Q100 series, designed for step-up (boost) and step-down (buck) topologies with a single adjustable output. Its internal switch is rated for 1.5 A continuous, and the device operates from a 3 V to 40 V input range, making it suitable for 12 V and 24 V automotive power rails. The fixed 100 kHz switching frequency is a trade-off: it keeps external inductor and capacitor sizes moderate, but limits the ability to shrink the solution footprint compared to newer 2 MHz+ parts.
The 1.5 A switch rating is the peak current the internal transistor can handle; the actual output current will be lower depending on the input-output voltage differential and topology — expect around 750 mA to 1 A in a typical buck from 24 V to 5 V. At 100 kHz, the inductor value will typically be in the 100 µH to 470 µH range, and the output capacitor in the 100 µF to 470 µF range — larger than what a 2.1 MHz regulator like the LMR33630APCQRNXRQ1 would require. The adjustable output voltage is set by two external resistors; the reference voltage is 1.25 V, so the output can be set anywhere from 1.25 V up to 40 V (limited by the switch rating).
Active production with AEC-Q100 traceability
Design-in checklist for the SOIC-8 layout
The 8-SOIC package has a 0.154-inch (3.90 mm) body width and a standard 1.27 mm pin pitch — a two-layer PCB can handle the fan-out, but a ground plane under the IC is recommended for thermal management. No synchronous rectifier is included, so an external Schottky diode is required for the buck topology — factor that into the BOM cost and board area. The input voltage range of 3 V to 40 V means the part can handle load-dump transients on a 12 V system, but a TVS clamp on the input is still advisable for severe spikes.