International journal of research in engineering and technology. Comparison of digital logic families important for electronics dic paper mumbaiu b. Logic family 3 schottky ls, internal resistance values were increased to reduce power consumption and increase switching speed over the original version. The same signal arriving at different parts of the design with different phase is known as skew. The transistortransistorlogic ttl family was developed in the use of transistor switches for logical operations and defines the binary values as. Low level state when lower transistor is on and upper transistor is off. Doshi, ce department 21004 digital electronics characteristics of digital ic threshold voltage the threshold voltage is defined as that voltage at the input of a gate which causes a change in the state of the output from one logic level to the other.
With about 20 logic families now extant, some comments are in order about which to use for teaching lab excercises and projects. Ttl is the largest family of digital ics, but the cmos family is growing rapidly. The basic circuit in the dtl logic is the nand gate. The goal of logic design or optimization is to find a network of logic gates which together compute the combinational logic function we want. A logic probe is a very useful tool for working with digital logic circuits. The 7400 series of integrated circuits ics were one of the most popular logic families of. Ttl logic in transistortransistor logic ttl, logic gates and other digital circuits are made using bipolar junction transistors and resistors. The popularity of these ttl families stem from their ease of use, low cost, mediumtohigh speed operation, and good output drive capability. What links here related changes upload file special pages permanent link page information wikidata. Here is a schematic diagram for a logic probe built using comparators. A program logic models have multiple sources of inspiration. Difference between ttl cmos ecl ttl vs cmos vs ecl.
Logic families electronics sandeep kumar singh bca iind semester 2. Many logic families were produced as individual components, each. Ttl stands for transistor transistor logic, cmos stands for complementary metal oxide semiconductor and ecl stands for emitter coupled logic. Introduction in digital electronics, a logic family refers to digital integrated circuit devices which are. 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 also have lower power requirements than the standard ttl these also have lower power requirements than the standard ttl overview integration, moores law early families dl, rtl t. The term transistortransistor is because both logic function and amplification is done by transis. A faster logic family called fast schottky f was also introduced that was faster than normal schottky ttl. Digital logic families electronics and communication. You are aware, i sincerely hope, that morse teaching center policy is to simplify ordering and to lessen confusion among tas and students by insisting on close adherence to a set of recommended parts. These families achieved pdps of 10 pj and 4 pj, respectively, the lowest of all the ttl families.
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. One source is early systems theory and efforts to conceptualize different stages or levels of results. Obviously, this base is predicated on the fact that we have ten fingers or digits. Logic operation is same as the open collector output. Its performance is a vast improvement over all other logic families. Logic families and their characteristics ee280 lecture 8 9 2 ttl transistortransistor logic standard logic family. Ecl is fabricated with unsaturated logic and lowlevel differential drive. Dtl offers better noise margins and greater fanouts than rtl resistor transistor logic, but suffers from low speed, especially in comparison to ttl. The introduction of advanced lowpower schottky als further increased speed and reduced power consumption. 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. A logic family has threshold voltage of 2 volts, minimum guaranteed output high voltage v oh 4 volts, minimum accepted input high voltage v ih 3 volts, maximum guaranteed output low voltage v ol 1 volt, and maximum accepted input low voltage v il 1.
Propositional and first order logic propositional logic first order logic basic concepts propositional logic is the simplest logic illustrates basic ideas usingpropositions p 1, snow is whyte p 2, otday it is raining p 3, this automated reasoning course is boring p i is an atom or atomic formula each p i can be either true or false but never both. Comparison of logic families using nand gate by ijret. I dont have the book and i dont remember anything else about it. Use of transistors q4 and diode is to provide quick charging and discharging of parasitic capacitance across q3. Ecl emitter coupled logic suitable for systems requiring highspeed operations mos.
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. P jain syllabus digital logic families characteristics of digital circuits. Integration levels gatetransistor ratio is roughly 110 ssi pdf 1 e. Logic families 8 auc 8 aup 9 alvc 9 aup1t 9 avc 10 lv1tlv4t 10lvclvc1g 11 acact 11 ahcahct 11 hchct 12 lvalvat. 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. A road map for your program that directs you at each step along your course. Because it connects the dots between resources, activities, and. Its the one we use to balance our checkbook and calculate the gas mileage of our automobiles. Many logic families has been produced as individual components, with each containing one or. Logic 1 and logic 0 are a bit more complex that 5v and 0v. An introduction to and comparison of 74hct ttl compatible cmos logic application note. Some logic families have been in the marketplace for years.
Low power schottky lsttl was the industry standard logic family for many years. Since its inception, several more modern families have come out, with equal or better performance. 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. Developing a logic model national responsible fatherhood. A graphic representation of how your program works.
Resistor is used to keep the output current to a safe value. The logic model is a valuable tool for program planning and development. 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. We may not have a logic gate for every possible function, or even for every function of. Evaluation of logic families using nor and nand logic gates. Page 1 chapter 5 part b digital logic families chapter 4 of r. A simple illustration of what you do, why and how you do it, and how you assess whether it works. Comparison of logic families for a 2input multiplexer. Clocked clocked cmos logic families vlsi systems and computer architecture lab. Transistortransistor logic ttl is a logic family built from bipolar junction transistors.
Ttl transistortransistor logic families history and. The logic model structure helps you think through your program strategyto help clarify where you are and where you want to be. These families vary by speed, power consumption, cost, voltage. Presentation on various logic families like rtl, dtl, ttl, iil etc with diagram. Cmoscmos integrated integrated circuit design techniques university of ioannina cmos logic families y. Transistortransistor logicttl, ttl nand gate with active pull up, its input and output.
Pdf on apr 20, 2017, shree krishna khadka and others published comparison of ic logic families find, read and cite all the research you. P jain page 2 chapter 5 part b digital logic families chapter 4 of r. Different circuit configurations and production technologies are used during the production of digital integrated circuits. Propositional and first order logic background knowledge. It indicates high and low logic states by means of leds, giving visual indication only if the voltage levels are appropriate for each state. Number systems and digital logic families we are all familiar with the common base 10 decimal number system. Dtl was first commercial available ic logic family in 5373 series. In computer engineering, a logic family may refer to one of two related concepts.
Each family has its own characteristics, limitations and advantages. A logic family of monolithic digital integrated circuit devices is a group of electronic logic gates constructed using one of several different designs, and with compatible logic levels and power supply characteristics within a family. 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. At one time, digital circuitry was composed almost entirely of standard functions, that is gates, latches, dividers, etc. Comparison of ic logic families logic gate mosfet free 30day. This ic is usually referred to as a monolithic ic first introduced in 1958.