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Practical Electronics/IC/4002

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4002
Logic Type Combinatorial
Function Family Logic
Description Dual 4-Input NOR Gate
Pins 14
Pinout
Functional Diagram

The 4002 is a member of the 4000 Series CMOS range, and contains two independent NOR gates, each with four inputs. The pinout diagram, given on the right, is the standard four-input CMOS logic gate IC layout:

  • Pin 7 is the ground supply (GND)
  • Pin 14 is the positive supply (VDD)
  • Pins 2-5 and 9-12 are gate inputs for the two gates
  • Pin 1 and 13 are gate outputs
  • Pin 6 and 8 are not connected

The truth table for one of the two gates is shown below. For more information about the NOR gate in general, see this module.

Truth Table for a Single Gate
A B C D Q
0 0 0 0 1
0 0 0 1 0
0 0 1 0 0
0 0 1 1 0
0 1 0 0 0
0 1 0 1 0
0 1 1 0 0
0 1 1 1 0
1 0 0 0 0
1 0 0 1 0
1 0 1 0 0
1 0 1 1 0
1 1 0 0 0
1 1 0 1 0
1 1 1 0 0
1 1 1 1 0

This chip is widely available, and usually comes in a DIL-14 or SOIC-14 package.

This chip is different in pinout to the TTL 7425, but can fulfill its function if the wiring is modified.