If all of the inputs to the AND gate are not HIGH, a LOW (0) is outputted.
The function can be extended to any number of inputs by multiple gates up in a chain.
The AND gate with inputs A and B and output C implements the logical expression
AND gates can also be made from discrete components and are readily available as integrated circuits in several different logic families.
AND gates with multiple inputs are designated with the same symbol, with more lines leading in.
[2] While direct implementations with more than four inputs are possible in logic families like CMOS, these are inefficient.
More efficient implementations use a cascade of NAND and NOR gates, as shown in the picture on the right below.