Comparison of logic families pdf

There are different families of logic gates in digital logic design. Overview integration, moores law early families dl, rtl ttl evolution of ttl family ecl. Transistor transistor logic ttl emitter coupled logic ecl cmos logic family. We can take as an example a 2input nand gate, numbered, appro. Comparing 7400 series to the 4000 series logic familes. Introduction of digital logic families miniature, lowcost electronics circuits whose components are fabricated on a single, continuous piece of semiconductor material to perform a highlevel function. Include a pin out diagram for the and logic function on ttl 7400 series and cmos 4000 series intergrated circuits. Ttl circuits utilize bjts bipolar junction transistors while cmos circuits utilize fets field effect transistors. Comparison of ic logic families free download as pdf file. They are the fundamental buildi integrated circuit devices can be constructed using sever different logic circuit families are compared. Difference between ttl cmos ecl ttl vs cmos vs ecl. Logic families logic families are sets of chips that may implement different logical functions, but use the same type of transistors and voltage levels for logical levels and for the power supplies. I will just quote a part from difference between cmos and ttl.

Ttl stands for transistor transistor logic, cmos stands for complementary metal oxide semiconductor and ecl stands for emitter coupled logic. Logic suppliers have historically focused on speed and low power as the priorities for product family improvement. This ic is usually referred to as a monolithic ic first introduced in 1958. 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. Ttl transistortransistor logic, made of bipolar transistors. There have been many improvements in logical families such as ttl and cmos. Ttl transistortransistor logic families history and. They deliver speed and drive on a par with ttl, quashing worries about highspeed systems built with cmos alone. Logic families are sets of chips that may implement different logical functions but use the same type of transistors and voltage levels for logical levels and for the power supplies. Diodes take up far less room than resistors, and can be constructed easily.

Logic families and their characteristics 1 objectives you should be able to. Laws of boolean algebra, duality theorem, demorgans theorem logic families. It draws a certain amount of current during its operation. In the figure below, clock signal clk reaches flipflop ff0 at time t0, so with respect to the clock phase at the source, it has at ff0 input a clock skew of t0 time units.

Ttl and cmos characteristics purpose logic gates are classified not only by their logical functions, but also by their logical families. Integration levels gatetransistor ratio is roughly 110 ssi 3. I dont have the book and i dont remember anything else about it. A fanout of 10 means that 10 unit loads can be driven by the gate while still maintaining the output voltage within specifications for logic levels 0 and 1. Dec 30, 2018 different circuit configurations and production technologies are used during the production of digital integrated circuits. Transistortransistor logic ttl is a logic family built from bipolar junction transistors. Xilinx offers a comprehensive multinode portfolio to address requirements across a wide set of applications.

The mechanisms by which they fail are different thanks. Jan 26, 2018 comparision of logic families watch more videos at lecture by. A comparison between the arabic and the english language. Compare and contrast the 7400 series and 4000 series logic familes with reference to at least 5 characteristics e.

Many logic families were produced as individual components, each. Ls ttl and hct or cmos, or if an older ttl ic is replaced by an. In digital designs, our primary aim is to create an integrated circuit ic. The logic families which fall under the first kind are called bipolar families, this include diode logic dl, emitted coupled logic ecl, resistor transistor logic rtl, diode transistor logic dtl, transistor transistor logic ttl. An introduction to digital logic families what is a logic family. Analyze internal circuitry of a ttl nand gate for both high and low output states. Ecl is based on use of current steering switch realised using differential transistor pair. Cmos logic family has become the most widely used logic families due to its numerous advantages such as less power consumption and low noise during transmission levels. Initially launched as straight 7400 series integrated circuits, this logic ic family has spawned many variants which has enabled it to remain in use until this day. Cmos complementary metal oxide semiconductor made from mosfets.

How can we compare and contrast ttl and cmos logic families. Unlike the other logic families in this chapter, ecl does not produce a large voltage swing between the low and high levels. Whether you are designing a stateofthe art, highperformance networking application requiring the highest capacity, bandwidth, and performance, or looking for a lowcost, small footprint fpga to take your softwaredefined technology to the next level, xilinx fpgas and 3d ics provide. Instead, it has a small voltage swing, less than a volt, and it internally switches current between two. Within each family, several subfamilies of logic types are available, with different. The ecl emitter coupled logic families, originated in the late 1950s and remain the fastest chips available, but consume more power, and because they use a negative power supply of. The major issue in any discussion of multiplecomparison procedures is the question of. It was build in 1961 by james l bui and commercially used in logic design in 1963. Working voltage, maximum frequency, threshold voltage for ones and zeros, fanin, fanout, power consumption. International journal of research in engineering and technology eissn. This page compares ttl vs cmos vs ecl logic families and mentions difference between ttl and cmos and ecl based on various parameters such as fanout,power consumption,noise immunity etc. The other two families are for military and industrial application. Comppggaring logic families major parameters for comparing logic families are the propagation delay, the power dissipation and the speedpower product.

Logic selection guide how to use this guide the data on this page page 2give an historic overview of fairchilds available logic families. A tabulation of the major logic families with relevant data is given. Each of these approaches is called a specific logic families. The popularity of these ttl families stem from their ease of use, low cost, mediumto. Diodetransistor logic dtl emitter coupled logic ecl logic families can be classified broadly according to the technologies they are built with transistortransistor logic ttl cmos logic ttl and cmos logic family is most widely used ic technologies. Now the bimos logic family is the one that uses both bipolar and mos devices. The time between the logic transition on an input and the corresponding logic transition on the output of the logic gate. For example, a certain amount of current is needed in order to operate correctly. The quick reference attributes charts on page 3may be a good.

The power dissipation of cmos logic deppyppgends heavily upon the operating frequency of the logic. In computer engineering, a logic family may refer to one of two related concepts. Pdf on apr 20, 2017, shree krishna khadka and others published comparison of ic logic families find, read and cite all the research you. A circuit configuration or arrangement of the circuit elements in a special manner will result in a particular logic family. This allows the designer to fabricate logic by connecting the opencollector outputs of several logic gates together and providing a single external pullup resistor. Cmos is sensitive to fanoutthe number of gates attached to the output of a driver gate. Its name signifies that transistors perform both the logic function the first transistor and the amplifying function the second transistor. Comparison of fieldeffect transistor logic families for a. Overview integration, moores law early families dl, rtl ttl evolution of ttl family ecl cmos family and its evolution overview 2.

The name is derived from the use of two bipolar junction transistors or bjts in the design of each logic gate. Integrated injection logic i 2 l family comparison of different logic families. These families vary by speed, power consumption, cost, voltage. Logic families are offered at every priceperformance node along with benchmark delivery, reliability, and worldwide support. Comparision of logic families watch more videos at lecture by. Ti maintains a firm commitment to remain in the market with both leadingedge and mature logic lines. Symbol, diodetransistor switch circuit and logical expression, truth table of basic gates and, or, not, universal gates nand, nor and special purpose gates exor, exnor, tristate logic. Logic gate circuits various logic families objective.

Now the idea of having different approaches or different logic families is that each ics of same family when fabricated will have identical electrical characteristics. The differences in the output voltage andor current levels for ttl and the cmos gates can affect circuit operation if both bipolar and cmos logic families are used in the same circuit e. Apr 16, 20 logic families the types of digital circuit devices are classified in families that based on the specific circuit technology. The increase in portable battery powered electronic devices along with the ability of chip manufacturers to make the component parts of ics much smaller also meant that power could be reduced and speed increased. Capacitor fet logic cfl has about one quarter of the power dissipation of bfl and occupies a similar area of gaas.

Digital logic families digital logic has evolved over the years and this process has led to the development of a variety of families of digital logic integrated circuits. If any of the logic gates becomes logic low transistor conducting, the combined output will be low. Each family has its own advantages and limitations. Logic guide introduction and contents todays applications are evolving with greater functionality and smaller size. Digital logic families phys3360aep3630 lecture 26 these also have lower power requirements than the standard ttl these also have lower power requirements than the standard ttl these. The types of logic devices are classified in families, of which the most important are ttl and cmos. Each ic family has its own characteristics, limitations and advantages. Difference between cmos and ttl compare the difference. It is possible to tell the logic family, the manufacturer and various other elements of the performance of the logic ic simply by looking at the number. Interconnecting any two logic families often required special techniques such as additional pullup resistors, or purposebuilt interface circuits, since the logic families may use different voltage levels to represent 1 and 0 states, and may have other interface requirements only met within the logic family. Over the years, the most widely used overall family has been the 7400 series ics. The same signal arriving at different parts of the design with different phase is known as skew.

Comparison of ic logic families logic gate mosfet scribd. The logic behind most of our post hoc tests, however, does not require overall significance before making specific comparisons. Ecl emitter coupled logic for extremely high speeds. Pdf comparison of logic families using nand gate editor. Logic families significance and types of logic families. Comparision of logic families watch more videos at comvideotutorialsindex. Buffered fet logic bfl is the most popular approach leading to gates that are fast and have good outputdrive capability, but they occupy a lot of space and consume a lot of power. In any implementation of a digital system, an understanding of a logic elements physical capabilities and limitations, determined by its logic family, are critical to proper operation. It has evolved from the original golddoped saturated 7400 logic, to schottkyclamped logic, and finally to the modern advanced families of ttl logic. Logic families and their characteristics website staff ui. Ppt logic families and their characteristics powerpoint.

Given this basic understanding of how these logic families work, we can set up a scenario in which each logic families fail. Among them, the most important ar slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Logic gates are manufactured in a range of logic families the ability of a gate to ignore noise is its noise immunity both mosfets and bipolar transistors are used in gates all logic gates exhibit a propagation delay when responding to changes in their inputs the most widely used logic families are cmos and ttl. Comparison of digital logic families important for electronics dic paper mumbaiu b. Difference between cmos and ttl difference between. Comparison of logic families using nand gate by ijret editor. Digital ic gates are classified not only by their logic operation, but also by the specific logic circuit family to which it belongs. This document describes the main logic families and their characteristics. To understand basic gate operation of following logic families. Tis goal is to help designers easily find the ideal logic technology or function they need. The method of analysis 180 the objects of philosophical analysis 180 three levels of analysis 181 the idea of a complete analysis 183 the need for a further kind of analysis 184 possibleworlds analysis 185 degrees of analytical knowledge 187 3. Logic families the types of digital circuit devices are classified in families that based on the specific circuit technology.

Nov 28, 20 table 1 comparison of different logic families it can be observed from table 1 that power dissipation in cmos logic is least as compared to all the logic families. Each gate is connected to a power supply vcc vdd in the case of cmos. Characteristics and comparison of digital ic electronics. Logic families digital electronics wiley online library. All the common microprocessors, microcontrollers, and integrated circuits use cmos technology. In rtl l transistor is used in conjunction with resistors to create a circuit.

Discuss the differences and proper use of the various. Commercially it starts with the 74 series like the 7404, 74s86 etc. Cmos logic families many families of logic exist beyond static cmos comparison of logic families for a 2input multiplexer briefly overview pseudonmos differential cvsl dynamicdomino complementary passgate. It is a logic family consisting completely of transistors.