74165 8-Bit Parallel-In/Serial-Out Shift Register

A 74165 integrated circuit providing a 8-bit parallel-in serial-out shift register. Reads eight parallel inputs and shifts them out serially, so a microcontroller can read eight buttons or switches using three pins. The input counterpart to the 74595. This is standard 74-series TTL logic, which runs specifically on 5 volts and is faster than 4000-series CMOS but draws considerably more current and will not tolerate other supply voltages. If your circuit runs at 3.3V or on batteries, ask us about the 74HC equivalent, which uses the same pinout and function but works from 2 to 6 volts at far lower current. Fast switching compared with 4000-series CMOS; Standard 16-pin DIP fits breadboards and sockets; Extensively documented in textbooks and coursework; Direct 5V logic compatibility with Arduino outputs