Transistor–transistor logic

Transistor–Transistor Logic (TTL) is a class of digital circuits built from transistors and resistors. It is called transistor–transistor logic because the logic function (e.g., AND) and amplification is performed by transistors. Many integrated circuits have TTL technology. They are used in applications such as computers, industrial controls, test equipment and instrumentation, synthesizers, etc.

TTL gates define a voltage below 0.5V as 0, and a voltage of 4–5V as 1.

 Series Type 

 Bipolar
 74 - the "standard TTL" logic family (long obsolete) had no letters between the "74" and the specific part number.
 74L - Low power (compared to the original TTL logic family), very slow (rendered obsolete by the LS-series)
 H - High speed (rendered obsolete by the S-series, used in 1970s era computers)
 S - Schottky (obsolete)
 LS - Low Power Schottky
 AS - Advanced Schottky
 ALS - Advanced Low Power Schottky
 F - Fast (faster than normal Schottky, similar to AS)
 CMOS
 C - CMOS 4-15V operation similar to 4000 series
 HC - High speed CMOS, similar performance to LS, 12nS
 HCT - High speed, compatible logic levels to bipolar parts
 AC - Advanced CMOS, performance generally between S and F
 AHC - Advanced High-Speed CMOS, three times as fast as HC
 ALVC - Low voltage - 1.65 to 3.3V, tpd 2nS
 AUC - Low voltage - 0.8 to 2.7V, tpd<1.9nS@1.8V
 FC - Fast CMOS, performance similar to F
 LCX - CMOS with 3V supply and 5V tolerant inputs
 LVC - Low voltage - 1.65 to 3.3V and 5V tolerant inputs, tpd<5.5nS@3.3V, tpd<9nS@2.5V
 LVQ - Low voltage - 3.3V
 LVX - Low voltage - 3.3V with 5V tolerant inputs
 VHC - Very High Speed CMOS - 'S' performance in CMOS technology and power
 G - Super high speeds at more than 1 GHz, 1.65V to 3.3V and 5V tolerant inputs, tpd 1nS (Produced by Potato Semiconductor)
 BiCMOS
 BCT - BiCMOS, TTL compatible input thresholds, used for buffers
 ABT - Advanced BiCMOS, TTL compatible input thresholds, faster than ACT and BCT

Category:Electronics