Comparison of different logic families pdf

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. Cmos circuits do not draw as much power as ttl circuits while at rest. Different logic families falling in the first category are called bipolar families,and these include diode logic dl, resistor transistor logic rtl, diode transistor logic dtl,transistor transistor logic ttl, emitter coupled logic ecl, also known as. Hi there, im trying to do an assignment on interfacing between different logic families. When interfacing different families, pay attention to their inputoutput voltage, current fanout specs. Cmos complementary metal oxide semiconductor is also another classification of ics that uses field effect transistors in the design. The characteristics which are bound to be identical are supply voltage range, speed of response, dissipation of power. Ecl is fabricated with unsaturated logic and lowlevel differential drive. The basic classification of the logic families are as follows.

Nov 28, 20 in this paper different logic circuit families are compared. As expected, the very early logic families and technologies have been discontinued, but many different logic types are available. Nor gate nand gate length power delay powerdelay product power delay powerdelay product 180nm 9. Comparison of logic families using nand gate by ijret editor. First of all, the hypotheses tested by the overall test and a multiple comparison test are quite different, with quite different levels of power. Jan 29, 20 different logic families falling in the first category are called bipolar families,and these include diode logic dl, resistor transistor logic rtl, diode transistor logic dtl,transistor transistor logic ttl, emitter coupled logic ecl, also known as current mode logic cml, and integrated injection logic i2 l. Different circuit configurations and production technologies are used during the production of digital integrated circuits. Comparision of logic families watch more videos at lecture by. Logic families significance and types electrical study. Logic families significance and types of logic families. Based on the graphic the 4000 series cmos family, and many of the ttl only families are moving to obsolescence. Given this basic understanding of how these logic families work, we can set up a scenario in which each logic families fail. Unless otherwise specified, fanout is always assumed to refer to load devices of the same family as the driving output.

Jul 27, 2007 logic families significance and types. First of all, the hypotheses tested by the overall test and a multiplecomparison test are quite different, with quite different levels of power. In other words, the different parameters like noise margin, fan in, fan out etc will be identical. While logic families like domino logic utilize clocked dynamic techniques to minimize the power consumption, size and delay. For example, a certain amount of current is needed in order to operate correctly. Sep 29, 2012 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.

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. The characteristics which are bound to be identical are supply voltage range, speed of response, dissipation of power, input and output logic levels, electric current sinking. An ideal example of ttl logic ic would be logic gate ics like the 7400 nand or the 7402 nor gate. Over the years some logic families have survived the struggle and. A bipolar families b mos families c hybrid devices. Ttl chips tend to consume a lot more power compared to cmos chips especially at rest.

The task is to identify the optimum solution for their application. Difference between cmos and ttl difference between. A family has its own power supply voltage and distinct logic levels. Logic families we have seen that different devices use different voltages ranges for their logic levels they also differ in other characteristics in order to assure correct operation when gates are interconnected they are normally produced in families the most widely used families are. What are the basic differences between cmos and ttl. The power dissipation of cmos logic deppyppgends heavily upon the operating frequency of the logic. Glue logic family selection which logic family do i need, why would i chose one logic family over another. Its performance is a vast improvement over all other logic families. However, the first cmos integrated circuit was not produced until 1968. A two input gate will have two emitters and a four input gate will have four emitters.

The idea is to first decompose elements of a by their relative ranks under r, afterwards linearly extend them with different rranks in ascending. Integrated injection logic i 2 l family comparison of different logic families. Comparison of digital logic families important for electronics dic paper mumbaiu b. Over the years, the most widely used overall family has been the 7400 series ics. Ttl is the short form of transistortransistor logic. Logic selection guide how to use this guide the data on this page page 2give an historic overview of fairchilds available logic families. Transistor transistor logic ttl emitter coupled logic ecl cmos logic family. 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.

Pdf on apr 20, 2017, shree krishna khadka and others published comparison of ic logic families find, read and cite all the research you need on researchgate. Why these different families exist dates back to the 1960s when groups of logic ics using different technologies first became available. The most commonly available logic ics are the 74 series family and its sub. In the process it is necessary to compare various semiconductor versions of logic gates. Some logic families have been in the marketplace for.

Tpd trisefall vih,min vil,max voh,min vol,max noise margin lifecycle rtl had economic advantage in that very. Logic families digital electronics wiley online library. 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. The output stage of most ttl logic is a totempole circuit. Even though most logic is contained within larger chips these days, there is still the need to small logic functions in many circuits. Interfacing between different logic families all about. Ics of different families can sometimes also be directly connected together, but may require some extra circuitry at the interface of the two ic families to maintain compatibility. Voltage levels range from 0 to vcc where vcc is typically 4. They deliver speed and drive on a par with ttl, quashing worries about highspeed systems built with cmos alone. Logic families and their characteristics website staff ui. In the late 1960s, when the standard ttl family offered 20 ns gate delay and the cmos 4000 family had delays of 100 ns or more, mecl10k offered 1 ns. In digital electronics, a logic family refers to digital integrated circuit devices which are constructed witha combination of electronic gates.

These consist of the 74xx, 74s, 74ls, 74as, 74als, 74f. The mechanisms by which they fail are different thanks. Jan 26, 2018 comparision of logic families watch more videos at lecture by. Power, delay and powerdelay power delay product are some of the performance parameters paramet used for comparison. Comparison of logic families using nand gate by ijret. The logic behind most of our post hoc tests, however, does not require overall significance before making specific comparisons.

As the world leader in logic, texas instruments ti offers a full spectrum of logic functions and technologies that range from the mature bipolar and bipolar complementary metaloxide semiconductor bicmos families to the latest advancedcmos families. Within each family, several subfamilies of logic types are available, with different rating for speed, power consumption. Power, delay and power delay power delay product are some of the performance parameters paramet. Comppggaring logic families major parameters for comparing logic families are the propagation delay, the power dissipation and the speedpower product. Logic families are sets of chips that may implement different logical functions, but. There have been many different families of logic ic and their associated technologies.

Designers can use many different solutions to solve the same problem. Ttl stands for transistor transistor logic, cmos stands for complementary metal oxide semiconductor and ecl stands for emitter coupled logic. Frank wanlass patented the invention in 1967 while working at rca, at that time. Integration levels gatetransistor ratio is roughly 110 ssi texas instruments logic guide 2017 3 0. Compare the characteristics of different logic families. 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. These differences can cause problems when you connect a gate from one. Working voltage, maximum frequency, threshold voltage for ones and zeros, fanin, fanout, power consumption. The marketplace has provided an environment for a struggle between different versions of logic chips. There have been many improvements in logical families such as ttl and cmos. In this case fanout is meaningless, unless the operating condition is specified exactly. An overview of ttl and cmos ics and how to choose between them. All types of glue logic families are still in mass production, but a number of families may soon be obsolete.

Here, both the functions logic and amplifying are performed by the transistors. The quick reference attributes charts on page 3may be a good. Hundreds of different, but directly interconnectable logic ics are available. Pdf comparison of logic families using nand gate editor. Below is a copy of a four year old graphic from a texas instruments. Compare and contrast the 7400 series and 4000 series logic familes with reference to at least 5 characteristics e. Include a pin out diagram for the and logic function on ttl 7400. Accordingly a variety of logic ic families spawned, each offering different capabilities and facilities. In this paper different logic circuit families are compared. Different ics belonging to the same logic families will be compatible with each other.

The same signal arriving at different parts of the design with different phase is known as skew. I dont have the book and i dont remember anything else about it. 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. Characteristics and comparison of digital ic electronics. When interfacing different families, pay attention. When the two logic families being interfaced have different power supplies then special circuits called level 9.

A comparison between the arabic and the english language. We have already argued in brief that the logic of comparative analysis is different from the logic of other forms of social science research, especially from the. Difference between cmos and ttl compare the difference. The main difference between analog and digital, is the latter operates on two levels only, 1 and 0. However, cmos power consumption increases faster with higher clock speeds than ttl does. Bipolar devices are the normal ttl series of devices. With more than 125 different standard gate functions and close to 40 little logic functions, ti has one of. Review the performance of complex digital circuits by considering the effects of using different logic families for interfacing between technologies and analogue systems. Comparing 7400 series to the 4000 series logic familes. 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. Table 2 shows the comparison of cmos logic families for different scalings in nor and nand logic. 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. We have already argued in brief that the logic of comparative analysis is different from the logic of other forms of social science research, especially from the statistical method that tends to dominate social research.

Evaluation of logic families using nor and nand logic gates. All the common microprocessors, microcontrollers, and integrated circuits use cmos technology. In addition, it is not uncommon for them to have a negative supply, e. 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. One major factor in the power consumption of a cmos circuit is the clock rate, with higher values resulting to higher power consumption.

This application report makes it easier for designers to do this. Overview ttl logic family cmos values typical for vccvdd 5v when interfacing different families, pay attention to their inputoutput voltage, current fanout specs. The ttl family the input of a ttl logic gate is characterized by a multi emitter transistor. Cmos vs ttl ttl stands for transistortransistor logic. 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. Ttl and cmos characteristics purpose logic gates are classified not only by their logical functions, but also by their logical families. There are different families of logic gates in digital logic design. Each ic family has its own characteristics, limitations and advantages. Modern mixedtechnology digital systems often employ logic from different logic families. Cmos is sensitive to fanoutthe number of gates attached to the output of a driver gate. Introduction 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 a logic family may also refer to a set of techniques. Comparision of logic families watch more videos at comvideotutorialsindex. The name is derived from the use of two bipolar junction transistors or bjts in the design of each logic gate.

Many logic families were produced as individual components, each containing one or a few related basic. Wh l i ttl nand i l h when at least one input to a ttl nand gate is low, the. An overview of ttl and cmos ics and how to choose between. The power consumption of a cmos chip can vary depending on a few factors.