MM74HC85

MM54HC85 MM74HC85 4-Bit Magnitude Comparator November 1995 MM54HC85 MM74HC85 4-Bit Magnitude Comparator General Description The MM54HC85 MM74HC85 is a 4-bit magnitude comparator that utilizes advanced silicon-gate CMOS technology It is designed for high speed comparison of two four bit words This circuit has eight comparison inputs 4 for each word three cascade inputs (AkB AlB A e B) and three decision outputs (AkB AlB A e B) The result of a comparison is indicated by a high level on one of the decision outputs Thus it may be determined whether one word is ‘‘greater than ’’ ‘‘less than ’’ or ‘‘equal to’’ the other word By connecting the outputs of the least significant stage to the cascade inputs of the next stage words of greater than four bits can be compared In addition the least significant stage must have a high level applied to the A e B input and a low level to the A kB and AlB inputs The comparator’s outputs can drive 10 low power Schottky TTL (LS-TTL) equivalent loads and is functionally and pin equivalent to the 54LS85 74LS85 All inputs are protected from damage due to static discharge by diodes to VCC and ground Features Y Y Y Y Y Typical propagation delay 27 ns Wide operating voltage range 2 – 6V Low input current 1 mA maximum Low quiescent current 80 mA maximum (74HC Series) Output drive capability 10 LS-TTL loads Connection Diagram Dual-In-Line Package TL F 5205 – 1 Order Number MM54HC85 or MM74HC85 Truth Table Comparing Inputs A3 B3 A3 l B3 A3 k B3 A3 e...