Comparators

The comparator is used to compare two 4-bit numbers that appear on the input pins (labelled 'A1', 'A2', ... and 'B1', 'B2', ...).

Key points:

• There are three output pins, one for each of the possible comparison results A>B (labelled 'G'), A=B (labelled 'E') and A<B (labelled 'L').
• Carry input pins can be used to compare numbers of more than 4 bits, too big for a single comparator to handle. There are three carry inputs labelled 'CG', 'CE' and 'CL'. If A and B are equal, each output is the same as its corresponding carry input. One comparator is used to compare the lower order bits. Its outputs are connected to the carry inputs of another comparator comparing the higher order bits.

See also:

• Logic family parts
• Simulation of Digital ICs
• Using electronics parts