TI 93S46PC

The '46 is a very high speed 6-bit identity comparator. The A = B output is HIGH when the Enable(E) is HiGH and the two 6-bit words are equal. Equality is determined by Exclusive-NOR circuits which individually compare the equivalent bits from each word. When any two of the equivalent bits from each word have different logic levels, the A = B output is Low. An active HlGH Enable (E) provides a means of fast ripple expansion. By connecting the A = B output of the first stage of the comparator to the enable of the next stage, the comparator can be expanded in 6-bit increments at an additional 4.5 ns per stage. An even faster expansion technique is achieved by connecting the A = B Outputs to a Schottky NAND gate. This method compares two words of up to 78 bits each in 15 ns (typical) using the '133 13-input Schottky NAND gate.