7400-series integrated circuits

A low-cost plastic package SN7400 series was introduced in 1966 which quickly gained over 50% of the logic chip market, and eventually becoming de facto standardized electronic components.

This part was made in various through-hole and surface-mount packages, including flat pack and plastic/ceramic dual in-line.

[7] Special-purpose TTL devices were used to provide interface functions such as Schmitt triggers or monostable multivibrator timing circuits.

Although the 7400 series was the first de facto industry standard TTL logic family (i.e. second-sourced by several semiconductor companies), there were earlier TTL logic families such as: The 7400 quad 2-input NAND gate was the first product in the series, introduced by Texas Instruments in a military grade metal flat package (5400W) in October 1964.

7400 series parts were constructed using bipolar junction transistors (BJT), forming what is referred to as transistor–transistor logic or TTL.

Newer series, more or less compatible in function and logic level with the original parts, use CMOS technology or a combination of the two (BiCMOS).

Originally the bipolar circuits provided higher speed but consumed more power than the competing 4000 series of CMOS devices.

As integrated circuits in the 7400 series were made in different technologies, usually compatibility was retained with the original TTL logic levels and power-supply voltages.

An integrated circuit made in CMOS is not a TTL chip, since it uses field-effect transistors (FETs) and not bipolar junction transistors (BJT), but similar part numbers are retained to identify similar logic functions and electrical (power and I/O voltage) compatibility in the different subfamilies.

The part numbers for 7400-series logic devices often use the following designators: For example, "SN5400N" signifies that the part is a 7400-series IC probably manufactured by Texas Instruments ("SN" originally meaning "Semiconductor Network"[104]) using commercial processing, is of the military temperature rating ("54"), and is of the TTL family (absence of a family designator), its function being the quad 2-input NAND gate ("00") implemented in a plastic through-hole DIP package ("N").

Some examples of FJ series are: The Soviet Union started manufacturing TTL ICs with 7400-series pinout in the late 1960s and early 1970s, such as the K155ЛA3, which was pin-compatible with the 7400 part available in the United States, except for using a metric spacing of 2.5 mm between pins instead of the 0.1 inches (2.54 mm) pin-to-pin spacing used in the west.

Instead of the ubiquitous black resin, they had a brownish-green body colour with subtle swirl marks created during the moulding process.

It was jokingly referred to in the Eastern Bloc electronics industry as the "elephant-dung packaging", due to its appearance.

Clones of the 7400 series were also made in other Eastern Bloc countries:[108] A number of different technologies were available from the Soviet Union,[107][114] [115] [116] [108] Czechoslovakia,[117] [110] Poland,[108][110] and East Germany.

Around 1990 the production of standard logic ceased in all Eastern European countries except the Soviet Union and later Russia and Belarus.