The 74LS21 is a Dual 4-Input AND Gate IC based on TTL logic. It provides high-speed logical operations and is ideal for combining multiple logic signals into a single output condition in embedded and digital control applications.
The 7402 Quad 2-Input NOR Gate IC integrates four independent NOR gates into a single 14-pin DIP package. It’s ideal for logic control applications, digital circuits, and embedded systems needing negative-logic processing.