Switching regulator with a 1.5A internal switch
The MC34063EBN is a monolithic switching regulator from STMicroelectronics that integrates a 1.5 A (switch) rated output transistor on-chip. It handles step-up (boost) and step-down (buck) topologies with a single external inductor and a handful of passives. The 33 kHz switching frequency keeps the external inductor physically small and the switching losses low, but the ripple at the output will be higher than a modern part — plan for a larger output capacitor or a post-filter if the load is noise-sensitive. The output is adjustable from a 1.25 V reference up to 38 V, and the configuration can be positive or negative rail, giving one part the flexibility to cover a buck or an inverter from the same BOM.
Through-hole 8-DIP package and temperature range
The 8-DIP (0.300", 7.62 mm) through-hole package is straightforward to hand-assemble and rework, and it suits prototyping, low-volume production, or repair sockets where a soldered QFN would be impractical. Lifecycle status is Active per STMicroelectronics, with ROHS3 compliance — no immediate last-time-buy risk, and the part is still a standard catalog item.
Design-in checklist for the MC34063EBN
The input voltage range is 3 V to 40 V, so an industrial rail is fine, but the 40 V absolute maximum means no margin for a higher-voltage bus. The 1.5 A switch current is the peak inductor current limit — the actual output current will be lower, especially in boost mode where the duty cycle multiplies the switch stress. No synchronous rectifier is integrated — the freewheeling diode is external. A Schottky diode with a low Vf at the peak current will keep the efficiency above typical levels in most buck designs. The inductor must be rated for the peak switch current, not just the DC load.