Active lifecycle — no last-time-buy scramble
The SN74HC166N: ROHS3 compliant — no exemption sunset to track. The part ships in tube packaging, consistent with through-hole DIP handling in automated insertion or manual assembly.
The SN74HC166N operates from 2V to 6V, covering the full 74HC supply range. This means it interfaces directly with legacy 5V TTL/CMOS buses and also works at 3.3V in mixed-voltage designs — no level translator needed when the MCU runs at 3.3V and the peripheral bus is 5V-tolerant. The wide margin also helps in battery-powered gear where the rail droops below 4.5V. Single-element, 8-bit parallel-in/serial-out shift register. The push-pull output drives CMOS inputs without an external pull-up resistor, and the serial output daisy-chains to additional stages for wider input expansion.
16-DIP through hole — breadboard and rework friendly
Package is 16-DIP, 0.300-inch body width, 7.62 mm lead pitch. This is the standard 300-mil DIP footprint — fits breadboards, prototyping boards, and wave-solder production. Through-hole means hand-rework is straightforward with a soldering iron; no hot-air station or reflow profile needed. For a low-volume or legacy BOM, this package keeps assembly costs down. The 74HC family is CMOS with typical noise immunity of 30% of VCC — the wide temperature grade does not degrade the logic thresholds significantly.