The 7400 series contains hundreds of devices that provide everything from basic
logic gates,
flip-flops, and counters, to special purpose bus transceivers and
arithmetic logic units (ALU). Specific functions are described in a
list of 7400 series integrated circuits. Some TTL parts were made with an extended military-specification temperature range. These parts are prefixed with
54 instead of
74 in the part number. The less-common
64 and
84 prefixes on
Texas Instruments parts indicated an industrial temperature range. Since the 1970s, new product families have been released to replace the original 7400 series. More recent TTL-compatible logic families were manufactured using
CMOS or
BiCMOS technology rather than TTL. Today,
surface-mounted CMOS versions of the 7400 series are used in various applications in electronics and for
glue logic in computers and industrial electronics. The original
through-hole devices in
dual in-line packages (DIP/DIL) were the mainstay of the industry for many decades. They are useful for rapid
breadboard-prototyping and for education and remain available from most manufacturers. The fastest types and very low voltage versions are typically
surface-mount only, however. The first part number in the series, the 7400, is a 14-pin IC containing four two-input
NAND gates. Each gate uses two input pins and one output pin, with the remaining two pins being power (+5 V) and ground. This part was made in various through-hole and surface-mount packages, including flat pack and plastic/ceramic dual in-line. Additional characters in a part number identify the package and other variations. Unlike the older
resistor–transistor logic integrated circuits, bipolar TTL gates were unsuitable to be used as analog devices, providing low gain, poor stability, and low input impedance. Special-purpose TTL devices were used to provide interface functions such as
Schmitt triggers or
monostable multivibrator timing circuits. Inverting gates could be cascaded as a
ring oscillator, useful for purposes where high stability was not required.
History 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: •
Sylvania Universal High-level Logic in 1963 •
Motorola MC4000 MTTL •
National Semiconductor DM8000 •
Fairchild 9300 series •
Signetics 8200 and 8T00 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. The pin assignment of this early series differed from the
de facto standard set by the later series in
DIP packages (in particular, ground was connected to pin 11 and the power supply to pin 4, compared to pins 7 and 14 for DIP packages). The 5400 and 7400 series were used in many popular
minicomputers in the 1970s and early 1980s. Some models of the DEC
PDP-series "minis" used the
74181 ALU as the main computing element in the
CPU. Other examples were the
Data General Nova series and
Hewlett-Packard 21MX, 1000, and 3000 series. In 1965, typical quantity-one pricing for the SN5400 (military grade, in ceramic welded
flat-pack) was around 22
USD. As of 2007, individual commercial-grade chips in molded epoxy (plastic) packages can be purchased for approximately US$0.25 each, depending on the particular chip. File:NXP-74AHC00D-HD-HQ.jpg|
Die of a 74AHC00D, manufactured by
NXP File:SN7400 1965.jpg|SN7400 die in the original flat package, manufactured by
TI File:TTL-00-die-schema.jpg|Die vs Schematic of a NAND gate in a 74H00 (
Darlington transistor is visbile on the right) File:7400 Circuit.svg|Schematic of one gate in a 7400 File:74LS00 Circuit.svg|Schematic of one gate in a 74LS00 File:Schéma DM74ALS00.png|Schematic of one gate in a 74ALS00 File:Logic ICs in size comparison.JPG|Size comparison of 74HC00 in DIP vs TSSOP package == Families ==