功能

• 74HCxx series C-MOS standard logic IC.
• Standard logic ICs were originally used to manufacture arbitrary logic circuits when LSI integration was low and PLDs were not available.
• The minimum units of logic circuits, such as NOT, AND, OR, FF, etc. are put into one circuit. Therefore, the electrical characteristics of input and output are standardized so that direct connection is possible for standard logic ICs of the same series.
• Generally, there are TTL and C-MOS, and since the voltage and current specifications of the input and output are different, it is necessary to devise the connection. (LSIs are usually adapted to either specification.) The speed and operating voltage may vary depending on the series.
• The 74HCxx series is a typical C-MOS variety. Unlike TTL such as 74LSxx, the operating voltage has a wide range, so both +5 V and +3.3 V can be used.