7400-Series Logic ICs Specification

1. Overview

The 7400-series is a large family of digital logic integrated circuits originally implemented in TTL (Transistor-Transistor Logic) and later expanded to include CMOS-compatible variants. These devices provide fundamental building blocks such as gates, flip-flops, counters, multiplexers, decoders, and bus transceivers.

7400-series ICs are widely used in retrocomputing, 6502/Z80 systems, glue logic, and educational designs.

2. Logic Families

3. Electrical Characteristics (Typical)

4. Standard Package Types

5. Common Logic Categories

5.1 Basic Logic Gates

5.2 Latches and Flip-Flops

5.3 Counters and Registers

5.4 Decoders and Multiplexers

5.5 Bus Interface and Glue Logic

6. Pin Numbering Convention

• DIP packages use counter-clockwise numbering
• Pin 1 identified by notch or dot

       ________
  1 °|       |° 14
  2 °|        |° 13
  3 °|        |° 12
  4 °|        |° 11
  5 °|        |° 10
  6 °|        |°  9
  7 °|________|°  8

7. Power and Ground Pins

8. Timing Characteristics (General)

9. Interfacing Notes

• TTL outputs reliably drive TTL inputs
• CMOS inputs must not float
• Use 74HCT when interfacing CMOS with TTL signals
• Decoupling capacitors (0.1 µF) required per IC

10. Typical Retrocomputer Applications

• Address decoding
• Chip-select generation
• Bus buffering
• Clock gating and control
• State machines

11. Absolute Maximum Ratings (Summary)

12. References

• https://www.ti.com/lit/ds/symlink/sn74ls00.pdf
• https://archive.org/details/TTLCookBook
• https://digilent.com/reference/test-and-measurement/analog-discovery-2/hardware-design-guide