4-bit magnitude comparator
Description
INTEGRATED CIRCUITS
74F85 4-bit magnitude comparator
Product specification IC15 Data Handbook 1994 Sep 27
Philips Semiconductors
Philips Semiconductors
Product specification
4-bit magnitude comparator
74F85
FEATURES
• High-impedance NPN base inputs for reduced loading
(20µA in High and Low states)
PIN CONFIGURATION
B3 IAB 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 VCC A3 B2 A2 A1 B1 A0 B0
• Magnitude comparison of any binary words • Serial or parallel expansion without extra gating
DESCRIPTION
The 74F85 is a 4-bit magnitude comparator that can be expanded to almost any length.
It compares two 4-bit binary, BCD, or other monotonic codes and presents the three possible magnitude results at the outputs.
The 4-bit inputs are weighted (A0–A3) and (B0–B3) where A3 and B3 are the most significant bits.
The operation of the 74F85 is described in the Function Table, showing all possible logic conditions.
The upper part of the table describes the normal operation under all conditions that will occur in a single device or in a series expansion scheme.
In the upper part of the table the three outputs are mutually exclusive.
In the lower part of the table, the outputs reflect the feed-forward conditions that exist in the parallel expansion scheme.
The expansion inputs IA>B, and IA=B and IA When used for series expansion, the A>B, A=B and AB, IA=B and IA Stages can be added in this manner to any length, but a propagation delay penalty of about 15ns is added with each additional stage.
For proper operation, the expansion inputs of the least significant word should be tied as follows: IA>B = Low, IA=B = High, and IA
A>B A=B A0ns
TYPICAL SUPPLY CURRENT (TOTAL) 40mA
74F85
ORDERING INFORMATION
DESCRIPTION 16-pin plastic DIP 16-pin plastic SO COMMERCIA...
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