Texas Instruments 4-circuit 2-input NAND gate CMOS DIP14

This is a 74HCxx series C-MOS standard logic IC. Standard logic ICs were originally used to create arbitrary logic circuits in the days before LSI integration density and PLDs. Each circuit contains several of the smallest logic circuit units, such as NOT, AND, OR, and FF, and multiple combinations are used as needed. Therefore, the electrical characteristics of the inputs and outputs are standardized to allow direct connection between standard logic ICs of the same series. Broadly speaking, there are TTL and C-MOS, and the input and output voltage and current specifications differ, requiring ingenuity for interconnection. (Usually, LSIs are designed to meet one of these specifications.) Additionally, speed and operating voltage vary depending on the series. The 74HCxx series is a representative C-MOS product. Unlike TTL products such as the 74LSxx, it has a wide operating voltage range, allowing it to be used with both +5V and +3.3V systems.