The 7400 series of integrated circuits (ICs) are the most popular logic families.In 1964, Texas Instruments introduced the first members of their ceramic package SN5400 series transistor–transistor logic (TTL) logic chips, later 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. Over the decades, many generations of pin-compatible descendant families evolved to include support for low power CMOS technology, lower supply voltages, and surface mount packages.
An integrated circuit or monolithic integrated circuit is a set of electronic circuits on one small flat piece of semiconductor material that is normally silicon. The integration of large numbers of tiny MOS transistors into a small chip results in circuits that are orders of magnitude smaller, faster, and less expensive than those constructed of discrete electronic components. The IC's mass production capability, reliability, and building-block approach to circuit design has ensured the rapid adoption of standardized ICs in place of designs using discrete transistors. ICs are now used in virtually all electronic equipment and have revolutionized the world of electronics. Computers, mobile phones, and other digital home appliances are now inextricable parts of the structure of modern societies, made possible by the small size and low cost of ICs.
In computer engineering, a logic family may refer to one of two related concepts. A logic family of monolithic digital integrated circuit devices is a group of electronic logic gates constructed using one of several different designs, usually with compatible logic levels and power supply characteristics within a family. Many logic families were produced as individual components, each containing one or a few related basic logical functions, which could be used as "building-blocks" to create systems or as so-called "glue" to interconnect more complex integrated circuits. A "logic family" may also refer to a set of techniques used to implement logic within VLSI integrated circuits such as central processors, memories, or other complex functions. Some such logic families use static techniques to minimize design complexity. Other such logic families, such as domino logic, use clocked dynamic techniques to minimize size, power consumption and delay.
Texas Instruments Incorporated (TI) is an American technology company that designs and manufactures semiconductors and various integrated circuits, which it sells to electronics designers and manufacturers globally. Its headquarters are in Dallas, Texas, United States. TI is one of the top-10 semiconductor companies worldwide, based on sales volume. Texas Instruments's focus is on developing analog chips and embedded processors, which account for more than 80% of their revenue. TI also produces TI digital light processing technology and education technology products including calculators, microcontrollers and multi-core processors. To date, TI has more than 45,000 patents worldwide.
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 logic parts were made with an extended military-specification temperature range. These parts are prefixed with 54 instead of 74 in the part number. A short-lived 64 prefix on Texas Instruments parts indicated an industrial temperature range; this prefix had been dropped from the TI literature by 1973. Since the 1970s, new product families have been released to replace the original 7400 series. More recent TTL logic families are developed using CMOS or BiCMOS technology rather than TTL.
In electronics, a logic gate is an idealized or physical device implementing a Boolean function; that is, it performs a logical operation on one or more binary inputs and produces a single binary output. Depending on the context, the term may refer to an ideal logic gate, one that has for instance zero rise time and unlimited fan-out, or it may refer to a non-ideal physical device.
In electronics, a flip-flop or latch is a circuit that has two stable states and can be used to store state information – a bistable multivibrator. The circuit can be made to change state by signals applied to one or more control inputs and will have one or two outputs. It is the basic storage element in sequential logic. Flip-flops and latches are fundamental building blocks of digital electronics systems used in computers, communications, and many other types of systems.
An arithmetic logic unit (ALU) is a combinational digital electronic circuit that performs arithmetic and bitwise operations on integer binary numbers. This is in contrast to a floating-point unit (FPU), which operates on floating point numbers. An ALU is a fundamental building block of many types of computing circuits, including the central processing unit (CPU) of computers, FPUs, and graphics processing units (GPUs). A single CPU, FPU or GPU may contain multiple ALUs.
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.[ citation needed ]
In electronics, glue logic is the custom logic circuitry used to interface a number of off-the-shelf integrated circuits. This is often achieved using common, inexpensive 7400- or 4000-series components. In more complex cases, a programmable logic device like a CPLD or FPGA might be used. The falling price of programmable logic devices, combined with their reduced size and power consumption compared to discrete components, is making them common even for simple systems. In addition, programmable logic can be used to hide the exact function of a circuit, in order to prevent a product from being cloned or counterfeited.
In microelectronics, a dual in-line package, or dual in-line pin package (DIPP) is an electronic component package with a rectangular housing and two parallel rows of electrical connecting pins. The package may be through-hole mounted to a printed circuit board (PCB) or inserted in a socket. The dual-inline format was invented by Don Forbes, Rex Rice and Bryant Rogers at Fairchild R&D in 1964, when the restricted number of leads available on circular transistor-style packages became a limitation in the use of integrated circuits. Increasingly complex circuits required more signal and power supply leads ; eventually microprocessors and similar complex devices required more leads than could be put on a DIP package, leading to development of higher-density chip carriers. Furthermore, square and rectangular packages made it easier to route printed-circuit traces beneath the packages.
A breadboard is a construction base for prototyping of electronics. Originally the word referred to a literal bread board, a polished piece of wood used for slicing bread. In the 1970s the solderless breadboard became available and nowadays the term "breadboard" is commonly used to refer to these.
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.
In digital electronics, a NAND gate (NOT-AND) is a logic gate which produces an output which is false only if all its inputs are true; thus its output is complement to that of an AND gate. A LOW (0) output results only if all the inputs to the gate are HIGH (1); if any input is LOW (0), a HIGH (1) output results. A NAND gate is made using transistors and junction diodes. By De Morgan's theorem, a two-input NAND gate's logic may be expressed as AB=A+B, making a NAND gate equivalent to inverters followed by an OR gate.
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.
In electronics, a Schmitt trigger is a comparator circuit with hysteresis implemented by applying positive feedback to the noninverting input of a comparator or differential amplifier. It is an active circuit which converts an analog input signal to a digital output signal. The circuit is named a "trigger" because the output retains its value until the input changes sufficiently to trigger a change. In the non-inverting configuration, when the input is higher than a chosen threshold, the output is high. When the input is below a different (lower) chosen threshold the output is low, and when the input is between the two levels the output retains its value. This dual threshold action is called hysteresis and implies that the Schmitt trigger possesses memory and can act as a bistable multivibrator. There is a close relation between the two kinds of circuits: a Schmitt trigger can be converted into a latch and a latch can be converted into a Schmitt trigger.
A ring oscillator is a device composed of an odd number of NOT gates in a ring, whose output oscillates between two voltage levels, representing true and false. The NOT gates, or inverters, are attached in a chain and the output of the last inverter is fed back into the first.
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 Electric Products was a U.S. manufacturer of diverse electrical equipment, including at various times radio transceivers, vacuum tubes, semiconductors, and mainframe computers such as MOBIDIC. They were one of the companies involved in the development of the COBOL programming language.
Motorola, Inc. was an American multinational telecommunications company founded on September 25, 1928, based in Schaumburg, Illinois. After having lost $4.3 billion from 2007 to 2009, the company was divided into two independent public companies, Motorola Mobility and Motorola Solutions on January 4, 2011. Motorola Solutions is generally considered to be the direct successor to Motorola, as the reorganization was structured with Motorola Mobility being spun off. Motorola Mobility was sold to Google in 2012, and acquired by Lenovo in 2014.
National Semiconductor was an American semiconductor manufacturer which specialized in analog devices and subsystems, formerly with headquarters in Santa Clara, California, United States. The company produced power management integrated circuits, display drivers, audio and operational amplifiers, communication interface products and data conversion solutions. National's key markets included wireless handsets, displays and a variety of broad electronics markets, including medical, automotive, industrial and test and measurement applications.
The 7400 quad NAND gate was the first product in the series, introduced by Texas Instruments in a military grade metal flat package (7400W) in October 1964. The extremely popular commercial grade plastic DIP (7400N) followed in the third quarter of 1966.
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 0.25 USD each, depending on the particular chip.
7400 series parts were constructed using bipolar transistors, 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. Bipolar devices are also limited to a fixed power supply voltage, typically 5 V, while CMOS parts often support a range of supply voltages.
Milspec-rated devices for use in extended temperature conditions are available as the 5400 series. Texas Instruments also manufactured radiation-hardened devices with the prefix RSN, and the company offered beam-lead bare dies for integration into hybrid circuits with a BL prefix designation.
Regular-speed TTL parts were also available for a time in the 6400 series – these had an extended industrial temperature range of −40 °C to +85 °C. While companies such as Mullard listed 6400-series compatible parts in 1970 data sheets, by 1973 there was no mention of the 6400 family in the Texas Instruments TTL Data Book. Some companies have also offered industrial extended temperature range variants using the regular 7400-series part numbers with a prefix or suffix to indicate the temperature grade.
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, but similar part numbers are retained to identify similar logic functions and electrical (power and I/O voltage) compatibility in the different subfamilies. Over 40 different logic subfamilies use this standardized part number scheme. [ page needed ]
Many parts in the CMOS HC, AC, and FC families are also offered in "T" versions (HCT, ACT, and FCT) which have input thresholds that are compatible with both TTL and 3.3 V CMOS signals. The non-T parts have conventional CMOS input thresholds, which are more restrictive than TTL thresholds. Typically, CMOS input thresholds require high-level signals to be at least 70% of Vcc and low-level signals to be at most 30% of Vcc. (TTL has the input high level above 2.0 V and the input low level below 0.8 V, so a TTL high-level signal is in the forbidden middle range for 5 V CMOS.)
The 74H family is the same basic design as the 7400 family with resistor values reduced. This reduced the typical propagation delay from 9 ns to 6 ns but increased the power consumption. The 74H family provided a number of unique devices for CPU designs in the 1970s. Many designers of military and aerospace equipment used this family over a long period and as they need exact replacements, this family is still produced by Lansdale Semiconductor.
The 74S family, using Schottky circuitry, uses more power than the 74, but is faster. The 74LS family of ICs is a lower-power version of the 74S family, with slightly higher speed but lower power dissipation than the original 74 family; it became the most popular variant once it was widely available. Many 74LS ICs can be found in microcomputers and digital consumer electronics manufactured in the 1980s and early 1990s.
The 74F family was introduced by Fairchild Semiconductor and adopted by other manufacturers; it is faster than the 74, 74LS and 74S families.
Through the late 1980s and 1990s newer versions of this[ which? ] family were introduced to support the lower operating voltages used in newer CPU devices.
|(VDD = 5 V)|
Part number schemes varied by manufacturer. 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") 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").
Many logic families maintain a consistent use of the device numbers as an aid to designers. Often a part from a different 74x00 subfamily could be substituted ("drop-in replacement") in a circuit, with the same function and pin-out yet more appropriate characteristics for an application (perhaps speed or power consumption), which was a large part of the appeal of the 74C00 series over the competing CD4000B series, for example. But there are a few exceptions where incompatibilities (mainly in pin-out) across the subfamilies occurred, such as:
Some manufacturers, such as Mullard and Siemens, had pin-compatible TTL parts, but with a completely different numbering scheme; however, data sheets identified the 7400-compatible number as an aid to recognition.
At the time the 7400 series was being made, some European manufacturers (that traditionally followed the Pro Electron naming convention), such as Philips/Mullard, produced a series of TTL integrated circuits with part names beginning FJ. 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. Another peculiarity of the Soviet-made 7400 series was the packaging material used in the 1970s–1980s. 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.[ citation needed ]
The Soviet integrated circuit designation is different from the Western series:
Before July 1974 the two letters from the functional description were inserted after the first digit of the series. Examples: К1ЛБ551 and К155ЛА1 (7420), К1ТМ552 and К155ТМ2 (7474) are the same ICs made at different times.
Clones of the 7400 series were also made in other Eastern Bloc countries:
A number of different technologies were available from the Soviet Union, °C to +85 °C (as opposed to −40 °C to +85 °C for the 6400 series).Czechoslovakia, Poland, and East Germany. The 8400 series in the table below indicates an industrial temperature range from −25
|Soviet Union||Czechoslovakia||Poland||East Germany|
Around 1990 the production of standard logic ceased in all Eastern European countries except the Soviet Union and later Russia and Belarus. As of 2016, the series 133, К155, 1533, КР1533, 1554, 1594, and 5584 were in production at "Integral" in Belarus,as well as the series 130 and 530 at "NZPP-KBR", 134 and 5574 at "VZPP", 533 at "Svetlana", 1564, К1564, КР1564 at "NZPP", 1564, К1564 at "Voshod", and 1564 at "Exiton" in Russia. The Russian company Angstrem manufactures 54HC circuits as the 5514БЦ1 series, 54AC as the 5514БЦ2 series, and 54LVC as the 5524БЦ2 series.
Transistor–transistor logic (TTL) is a logic family built from bipolar junction transistors. Its name signifies that transistors perform both the logic function and the amplifying function ; it is the same naming convention used in resistor–transistor logic (RTL) and diode–transistor logic (DTL).
N-type metal-oxide-semiconductor logic uses n-type MOSFETs to implement logic gates and other digital circuits. These nMOS transistors operate by creating an inversion layer in a p-type transistor body. This inversion layer, called the n-channel, can conduct electrons between n-type "source" and "drain" terminals. The n-channel is created by applying voltage to the third terminal, called the gate. Like other MOSFETs, nMOS transistors have four modes of operation: cut-off, triode, saturation, and velocity saturation.
Complementary metal–oxide–semiconductor (CMOS), also known as complementary-symmetry metal–oxide–semiconductor (COS-MOS), is a type of MOSFET fabrication process that uses complementary and symmetrical pairs of p-type and n-type MOSFETs for logic functions. CMOS technology is used for constructing integrated circuits (ICs), including microprocessors, microcontrollers, memory chips, and other digital logic circuits. CMOS technology is also used for analog circuits such as image sensors, data converters, RF circuits, and highly integrated transceivers for many types of communication.
In digital logic, an inverter or NOT gate is a logic gate which implements logical negation. The truth table is shown on the right.
The 4000 series is a CMOS logic family of integrated circuits (ICs) first introduced in 1968 by RCA. Almost all IC manufacturers active during this initial era fabricated models for this series. It is still in use today.
In digital electronics, the fan-out of a logic gate output is the number of gate inputs it can drive.
In electronics, pin-compatible devices are electronic components, generally integrated circuits or expansion cards, sharing a common footprint and with the same functions assigned or usable on the same pins. Pin compatibility is a property desired by systems integrators as it allows a product to be updated without redesigning printed circuit boards, which can reduce costs and decrease time to market.
Resistor–transistor logic (RTL) is a class of digital circuits built using resistors as the input network and bipolar junction transistors (BJTs) as switching devices. RTL is the earliest class of transistorized digital logic circuit used; other classes include diode–transistor logic (DTL) and transistor–transistor logic (TTL). RTL circuits were first constructed with discrete components, but in 1961 it became the first digital logic family to be produced as a monolithic integrated circuit. RTL integrated circuits were used in the Apollo Guidance Computer, whose design was begun in 1961 and which first flew in 1966.
The OR gate is a digital logic gate that implements logical disjunction – it behaves according to the truth table to the right. A HIGH output (1) results if one or both the inputs to the gate are HIGH (1). If neither input is high, a LOW output (0) results. In another sense, the function of OR effectively finds the maximum between two binary digits, just as the complementary AND function finds the minimum.
In integrated circuits, depletion-load NMOS is a form of digital logic family that uses only a single power supply voltage, unlike earlier nMOS logic families that needed more than one different power supply voltage. Although manufacturing these integrated circuits required additional processing steps, improved switching speed and the elimination of the extra power supply made this logic family the preferred choice for many microprocessors and other logic elements.
The XNOR gate is a digital logic gate whose function is the logical complement of the exclusive OR (XOR) gate. The two-input version implements logical equality, behaving according to the truth table to the right, and hence the gate is sometimes called an "equivalence gate". A high output (1) results if both of the inputs to the gate are the same. If one but not both inputs are high (1), a low output (0) results.
In digital circuits, a logic level is one of a finite number of states that a digital signal can inhabit. Logic levels are usually represented by the voltage difference between the signal and ground, although other standards exist. The range of voltage levels that represents each state depends on the logic family being used.
A logic probe is a hand-held test probe used for analyzing and troubleshooting the logical states of a digital circuit.
P-type metal-oxide-semiconductor logic uses p-channel metal-oxide-semiconductor field effect transistors (MOSFETs) to implement logic gates and other digital circuits. PMOS transistors operate by creating an inversion layer in an n-type transistor body. This inversion layer, called the p-channel, can conduct holes between p-type "source" and "drain" terminals.
HCMOS is the set of specifications for electrical ratings and characteristics, forming the 74HC00 family, a part of the 7400 series of integrated circuits.
A level shifter in digital electronics, also called logic-level shifter or voltage level translation, is a circuit used to translate signals from one logic level or voltage domain to another, allowing compatibility between ICs with different voltage requirements, such as TTL and CMOS. Many modern full featured systems use level shifters to bridge domains between processors, logic, sensors, and other circuits. In recent years, the three most common logic levels are 1.8V, 3.3V, 5V, though other levels exist above and below these voltages too.
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