74 and 54 Series ICs all have a code on the top of the carrier body. This can be printed (usually in white) or etched. It consists of a "core" code which identifies the IC's function, and the type of electronics used within it. This is often supplemented by manufacturer's prefixes and suffixes which give information about the manufacturer and the carrier's physical form.
Core Code
Device Family
- 74 means a "commercial grade" device, suitable for general use.
- 54 means a "military grade" device, for use in more hostile environments.
Device Type
| Code | Meaning |
|---|---|
| TTL | |
| (none) | Standard TTL |
| N | Standard TTL |
| L | Low-power TTL |
| S | Schottky TTL |
| LS | Low-power Schottky TTL |
| AS | Advanced Schottky TTL |
| ALS | Advanced Low-power Schottky TTL |
| F | Fast TTL |
| CMOS | |
| C | CMOS |
| HC | High-speed CMOS, inputs CMOS compatible |
| HCT | High-speed CMOS, inputs TTL compatible |
| AC | Advanced CMOS, inputs CMOS compatible |
| ACT | Advanced CMOS, inputs TTL compatible |
| AHC | Advanced High-speed CMOS, inputs CMOS compatible |
| AHCT | Advanced High-speed CMOS, inputs TTL compatible |
| LV | Low-voltage CMOS |
| LVC | Low-voltage CMOS |
| ALVC | Advanced Low-voltage CMOS, inputs CMOS compatible |
| ALVT | Advanced Low-voltage CMOS, inputs TTL compatible |
| AUC | Advanced Ultra-Low-voltage CMOS |
| AUP | Advanced Ultra-Low-power CMOS |
| AVC | Advanced Very-Low-voltage CMOS Logic |
| FCT | Fast CMOS |
| GTLP | Gunning Transceiver Logic Plus |
| BiCMOS | |
| BCT | BiCMOS |
| ABT | Advanced BiCMOS |
| LVT | Low-Voltage BiCMOS |
| ALB | Advanced Low-Voltage BiCMOS |
| ABTE | Advanced BiCMOS / Enhanced Transceiver Logic |
| FB | Backplane Transceiver Logic |
| GTL | Gunning Transceiver Logic |
| HSTL | High-speed Transceiver Logic |
| SSTL | Stub Series Terminated Logic |
| SSTU | Stub Series Terminated Logic (Ultra-Low-voltage) |
| SSTV | Stub Series Terminated Logic (Very-Low-voltage) |
Device Function
This code tells you what the IC does. There are hundreds of these codes. Many common ones are given on the 74 Series page.
Manufacturer Information
Prefix
This tells you which company made the IC. There a many hundred of different prfixes, and dozens of manufacturers, some sharing the same prefix. As these prefixes are not unique to the 74 Series of ICs, these prefixes are listed separately and can be found here.
Suffix
This tells you the type of package that the IC comes in, for example a DIP. It can also give information about the material (e.g. ceramic or plastic). These suffixes are not unique to the 74 Series of ICs, and as such, they are listed on a separate page, here.