• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Logic gates

Extracts from this document...


Task 1 For each of the gates listed below, explain their operation showing appropriate gate symbols, truth tables and logic equations for the outputs in terms of the input variables. a) Two input OR gate Logic gates process signals which represent true or false. Normally the positive supply voltage +Vs represent true and 0V represents false. Other terms which are used for the true and false states are shown in the table on the right. It is best to be familiar with them all. The output Q is true if input A OR input B is true (or both of them are true): Q = A OR B An OR gate can have two or more inputs, its output is true if at least one input is true. Input A Input B Output Q 0 0 0 0 1 1 1 0 1 1 1 1 Traditional symbol IEC symbol Truth Table b) Two input AND gate The AND gate is a digital logic gate that implements logical conjunction - it behaves according to the truth table to the right. ...read more.


the NOR gate Z = A.B.C + A.B.C + A.B.C + A.B.C A B C Z 0 0 0 1 0 0 1 1 0 1 0 1 0 1 1 0 1 0 0 1 1 0 1 0 1 1 0 0 1 1 1 0 Task 5 For this task I was asked to produce a minimized circuit. I did this by using the karnaugh map below. BC A 00 01 11 10 0 1 1 1 1 1 The minimized equation for this circuit is: A.B + A.C + B.C I built this circuit, using the same equipment as previous, such as the logic probe etc. this circuit does the function as the original circuit, but only this time there are less components used. This has many benefits, as it makes the entire circuit cheaper to build, and the person building the circuit is less likely to make a mistake in the construction of it. Task 6 Compare and contrast, with reference to five characteristics the differences between the 2 types of logic family listed below. ...read more.


On the CMOS, the delay ranges from 95-40ns. The propagation delay time, is the time it takes to send the signal from the sender to the receiver. TTL would be the best suited for changing signal outputs quickly. The TTL supply current ranges from 11-33mA. CMOS ranges from 1-30A. the CMOS chip requires less amps to operate, so for it would be better suited for low power circuits. The TTL needs 4.75-5.25V, whilst CMOS chip requires between 3-15V. this means the CMOS chip would be the best for altering voltage. This makes CMOS the most useful. TTL can operate at a temperature range of 0-70C. The CMOS chip again beats this, because it has a superior temperature operating range of -40-+85C. CMOS wins this because it is best suited to large temperature changes. The high level output voltage on the TTL chip is 2.4v, whilst the CMOS has an output voltage, of 2 thirds that of the input voltage. E.g. if the input voltage is 5V, the output is 3.333V. In conclusion I feel that the CMOS chip is the superior chip for today's demands. The only area that CMOS is outperformed by TTL is the Propagation Delay Time. This means CMOS is a great chip. ?? ?? ?? ?? Gavin O'Hara ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Design and Technology section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Design and Technology essays

  1. Bedside table development evaluation

    The design will cost 143.80 to make if I was making a one-off production, however If designing in industry this product would be batch manufactured, due to cheaper material cost, more being made in a shorter time etc, so

  2. Printed Circuit Boards.

    The next step is etching. In this stage removing the exposed copper creates the final Printed Circuit Board. In order to etch the board, it must be sub merged in an etchant (a chemical solution, which removes the exposed copper from the board).

  1. The Characteristics and Development of RFID - Radio frequency identification.

    As a result, this will enable appropriate warehouse and distribution centre managers to use hand held devices to locate goods and to improve the efficiency of locating and picking goods. Retailers will be able to know where pallets and cased of goods are, to know if they have been stolen

  2. Nano technology - Screen technology is a fast changing technology area.

    LCoS LCD and DLP are small compared with the next couple of technology developments for rear-projection TVs. The first, liquid on silicon (LCoS) technology, offers a huge leap in quality. With LCoS, light is shone through a polarising filter and is deflected (or not)

  1. It is important that Sarah is blind having access to speech and Braille output ...

    The Braille fascinated me. I would sit down and write letters to everyone that they would work out. They were all impressed. Several months later, I thought to myself, "Why stop now?" and I learned Grade II Braille. The newest entries in my phone book are in Grade II Braille.

  2. Research in the uses of silicon

    It is similar to glass in that it is rather strong, very brittle, and prone to chipping. Even though it is a relatively inert element, silicon still reacts with halogens and dilute alkalis, but most acids (except for a combination of nitric acid and hydrofluoric acid) do not affect it.

  1. Devlopment evaluation of my bedside table.

    by making it this height my target market can put items in standing up, instead of lying flat, which save more space and allow more items to be stored in drawer. > The width of the table top should be 600mm an the length of table top should be 600mm

  2. The Differences and Assimilation of Chinese and American Diet

    Third, sauces made from soy beans are important in Chinese people?s daily life too. It is used to add flavor to all kind things Chinese people eat; it can be made into black bean sauce, soy sauce, oyster sauce, and fish sauces.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work