Lecture 7 specifications of logic circuits youtube. The 4000a cmos family has been replaced by its highvoltage versions in the 4000b and 4000ub cmos families, with the former having buffered and the latter having unbuffered outputs. For example, a certain amount of current is needed in order to operate correctly. The power dissipation of cmos logic deppyppgends heavily upon the operating frequency of the logic. Instead, it has a small voltage swing, less than a volt, and it internally switches current between two. There are various logic families namely diode logic dl resistortransistor logic rtl 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.
A logic family is a collection of different integratedcircuit chips that have similar input, output, and. So im going to have as inputs, the six digits of the first binary numbera 5 down through a 0 and then the second binary number. Overview integration, moores law early families dl, rtl ttl evolution of ttl family ecl. Digital electronics part i combinational and sequential logic. In this article, you will find the study notes on logic families which will cover the topics such as integrated circuits, characteristics of digital circuits, logical families, digital ic terminology, dl, rtl, dtl and ttl. Nptel video lectures, iit video lectures online, nptel youtube lectures, free video lectures, nptel online courses, youtube iit videos nptel courses. Integration levels gatetransistor ratio is roughly 110 ssi logic functions sop and pos forms. The current drive of the transistor gatetosource voltage is reduce significantly as v s approaches v ddv tn the current available to charge up node s. Aug 31, 2019 in this article, you will find the study notes on logic families which will cover the topics such as ecl, mos inverter, nand and nor with nmos, cmos, nand and nor with cmos, logic families comparison.
The simplest fct logic element is a 74fct8t decoder, which has six inputs, eight outputs, and contains the equivalent of about a dozen 4input gates internally. Cmoslogic digital logic families electronics tutorial. The ttl family the input of a ttl logic gate is characterized by a multi emitter transistor. We provided the download links to digital logic design books pdf download b. Share this article with your classmates and friends so that they can also follow latest study materials and notes on engineering subjects. Digital integrated circuits nptel online videos, courses.
Comppggaring logic families major parameters for comparing logic families are the propagation delay, the power dissipation and the speedpower product. Diode logic dl diode logic dl is the most primitive of all the digital logic families. V s will initially charge up quickly, but the tail end of the transient is slow. Logic families introduction to different logic families. The output stage of most ttl logic is a totempole circuit. Logic gates in cmos indepth discussion of logic families in cmosstatic and dynamic, passtransistor, nonran tioed and ratioed logic n optimizing a logic gate for area, speed, energy, or robustness lowpower and highperformance circuitdesign techniques 6.
Simple digital logic gates can be made by combining transistors, diodes and resistors as discrete components. Standard ttl 74 xxxll, low power ttl 74lxx low power schottky. Let us investigate some of such circuits using diode. Nptel video lectures, iit video lectures online, nptel youtube lectures. These families vary by speed, power consumption, cost, voltage. Logic familiespart i a conceptual video lecture youtube. Totem pole outputs open collector outputs open collector advantages. Which logic family has the highest power dissipation per gate a.
In this article, you will find the study notes on logic families which will cover the topics such as ecl, mos inverter, nand and nor with nmos, cmos, nand and nor with cmos, logic families comparison. Lecture 8 qualitative discussion on ttl circuits youtube. These characteristics may involve power, current, logical function, protocol and. 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. It is extremely simple and inexpensive because it only uses passive components. In computer engineering, a logic family may refer to one of two related concepts. Digital logic designers build complex electronic components that use both electrical and computational characteristics. Each ic family has its own characteristics, limitations and advantages. Amitava dasgupta, department of electrical engineering,iit madras. Dynamic power dissipation short circuit power switching power gliching power static power dissipation degrees of freedom supply voltage scaling. Logic families electronics sandeep kumar singh bca iind semester 2.
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. A two input gate will have two emitters and a four input gate will have four emitters. Logic families significance and types of logic families. Electrical engineering digital integrated circuits nptel. Mixing logic families wire anding of outputs bidirectional communication. Mos transistor structure and device modeling mos inverters mos combinational circuits different logic families sources of power dissipation. In this, each logic stage contains pull up and pull down networks which are. It is designed for the undergraduate students pursuing courses in areas of engineering disciplines such as electrical and electronics, electronics and communication, electronics and instrumentation. Logic families can be classified broadly according to the technologies they are built with. Analog to digital and digital to analog converters. Integration levels gatetransistor ratio is roughly 110 ssi study materials, books, for engineering students. The basic circuit in the dtl logic is the nand gate. Digital logic design university of california, davis.
It contains well written, well thought and well explained computer science and programming articles, quizzes and practicecompetitive programmingcompany interview questions. This ic is usually referred to as a monolithic ic first introduced in 1958. Logic families1 study notes for electronics and communication. Jan 16, 20 dtl was first commercial available ic logic family in 5373 series. 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.
Logic levels are the voltage levels for logic high and logic low. 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. Emittercoupled logic ecl based on bipolar transistors, but removes problems of storage time by preventing the transistors from saturating. 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.
Simplification of switching functions kmap and quinemccluskey tabular methods. 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. Open collector output terry sturtevant wilfrid laurier university october 3, 2018. There are different families of logic gates in digital logic design. So now lets try to design a bit of circuitry using digital logic signals of 0 and 1, which will do addition. There have been many improvements in logical families such as ttl and cmos. The direction of data transfer over the bus is signaled by the logic level output at dtr. The transistortransistor logic ttl family was developed in the use of transistor switches for logical operations and defines the binary values as. In this article, you will find the study notes on logic families which will cover the topics such as integrated circuits, characteristics of digital. Logic familiespart i a conceptual video lecture bipolar logic digital circuits. Unlike the other logic families in this chapter, ecl does not produce a large voltage swing between the low and high levels. Ttl is the largest family of digital ics, but the cmos family is growing rapidly.
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. Digital logic families digital integrated circuits are classified not only by their complexity or logical operation, but also by the specific circuit technology to which they belong. Ecl emitter coupled logic suitable for systems requiring highspeed operations mos metal oxide semiconductor logic. When this line is logic 1 during the data transfer part of a bus cycle, the bus is in the transmit mode. Integrated circuits integrated circuits ics are chips, pieces of semiconductor material, that contain all of the transistors, resistors, and capacitors necessary to.
The most common design style in modern vlsi design is the static cmos logic style. Introduction to fuzzy logic, by franck dernoncourt home page email page 2 of20 a tip at the end of a meal in a restaurant, depending on the quality of service and the quality of the food. Logic 1 at this output signals a memory operation and logic 0 an io operation. Later, we will study circuits having a stored internal state, i. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. In fact, it combines diodes and resistors so sometimes it is known as dioderesistor logic drl. Many logic families were produced as individual components, each. Therefore, data are either written into memory or output to an io. Digital logic design is foundational to the fields of electrical engineering and computer engineering. Lecture series on digital integrated circuits by dr. Fill in the banks of the statements below concerning the following logic families. Anand kumar the new edition of this wellreceived text continues to provide coherent and comprehensive coverage of digital circuits. Feb 12, 20 an introduction to digital logic families.
Since dl does not use active components such as transistors, it does not provide. Overview integration, moores law early families dl, rtl ttl evolution of ttl family ecl cmos family and its evolution overview 2. Dec 30, 2018 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. Jul 21, 2008 lecture series on digital integrated circuits by dr. Digital integrated circuits digital integrated circuits. Logic families and their characteristics ee280 lecture 8 9 2 ttl transistortransistor logic standard logic family. It contains well written, well thought and well explained computer science and programming articles, quizzes and practicecompetitive programmingcompany interview. Wh l i ttl nand i l h when at least one input to a ttl nand gate is low, the. Digital logic family there are various logic families namely diode logic dl resistortransistor logic rtl 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.
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