The CD4049UBD is a hex inverter from the 4000B CMOS logic family, containing six independent inverter gates each with a single input. It operates from a 3V to 18V supply range, making it suitable for battery-powered or unregulated-rail designs where a 5V-only gate would drop out.
The 3V to 18V supply range is the headline feature — it lets this inverter work from a 3.6V Li-ion cell down to near depletion, or from a 12V industrial rail without a regulator. The 4 µA quiescent current (max) keeps the standby draw negligible in battery-backed systems. Output drive is asymmetric: 4.3 mA sourcing and 24 mA sinking at rated supply, which means it can directly drive a low-power LED or a CMOS input but not a relay coil without a buffer. Propagation delay is 50 ns at 15V with a 50 pF load — that is about 10x slower than a 74AC gate, so it is a poor fit for high-speed clock trees or fast bus interfaces, but perfectly adequate for panel switch debounce, level translation, or enable logic running below a few MHz.
The CD4049UBD is supplied in a 16-pin SOIC package (0.154" body width, 3.90 mm) with a surface-mount footprint. The supplier device package is 16-SOIC. This is a standard SOIC-16 layout shared across many 4000B and 74HC series parts, so the PCB footprint is well-established and easy to route. No exposed pad — thermal management is straightforward for a CMOS gate drawing microamps.
There is no last-time-buy or obsolescence risk on this line. The 4000B series has been manufactured for decades and remains a staple for low-speed, wide-voltage, high-temperature logic. For dual-sourcing resilience, the CD4049UBD is a standard 4000B inverter — functionally equivalent to other manufacturers' 4049UB devices in the same package, though pin compatibility should be verified against the specific alternate order code.