The CD4503BPW is a non-inverting buffer from the 4000B CMOS logic family, in a 16-TSSOP surface-mount package. It contains two buffer elements: one with two inputs and one with four inputs (hex configuration), all with push-pull outputs.
3V to 18V supply — why it matters for your BOM
The 3V to 18V operating range is the defining spec of the 4000B family. Unlike 74HC or 74HCT parts that clamp to 5V or 6V, this buffer can interface directly with 12V or 15V logic rails common in older industrial equipment, or run from a lithium-ion cell stack that swings from 9V down to 6V. The push-pull outputs source 14.1 mA and sink 23 mA at 5V — enough to drive a CMOS input or a small LED, but not a 50Ω backplane. If you need 3-state outputs or higher drive, the CD74HCT241M (4.5V supply, 6 mA) or the 74FCT541 (4.75V, 15 mA) are functional alternatives, though neither matches the voltage range.
Military temperature range — deployment context
The 4000B process handles the thermal swing without the latch-up sensitivity of older CMOS. Keep the board clean and conformal-coated if condensation is a risk — the 16-TSSOP package is MSL 1 per the 4000B family typical, but the narrow 4.40 mm body demands a clean solder paste stencil for reliable reflow.
Lifecycle and sourcing posture
For dual-sourcing resilience, the CD74HCT241M (4.5V supply, 6 mA output) is a functional cross-shop candidate but not a pin-for-pin second source — the 16-TSSOP footprint and push-pull output are specific to this 4000B variant.