Integrated Circuit. Transistor Transistor Logic (TTL). 4−Line−to−16−Line Decoder /Demultiplexer. 24−Lead DIP Type Package. Description: The NTE is a. 1) CPD is defined as the value of the IC’s internal equivalent capacitance which is calculated from the operating current consumption without load. (Refer to Test . datasheet, circuit, data sheet: NSC – 4-Line to Line for Electronic Components and Semiconductors, integrated circuits, diodes, triacs.

Author: Gogami Mauhn
Country: Egypt
Language: English (Spanish)
Genre: Finance
Published (Last): 28 May 2006
Pages: 384
PDF File Size: 10.92 Mb
ePub File Size: 7.86 Mb
ISBN: 638-7-80191-320-5
Downloads: 96545
Price: Free* [*Free Regsitration Required]
Uploader: Akinolabar

Rather than providing only a single enable, both pins are used.

4 to 16 decoder logic diagram – Electrical Engineering Stack Exchange

This carried through to the input current requirements: As for the NAND gates, there is a function being implemented in which the gates are there to realize it. By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service. If you datashedt to know exactly what is going on then draw out the truth table, but it is unlikely their function will make much sense to you.

Please consider upvoting those questions you found useful like dstasheet one by clicking the arrow pointing up near the answer vote count which is in turn above the checkbox you clicked to accept this question.

Why is the output in the truth table inverted in a ic used as a demux? And that’s what is going on with the Many TTL parts and older memory chips have active low enable inputs, so the active low outputs of this part can be connected directly to those inputs.

WhatRoughBeast 49k 2 28 For example, if the target application requires 16 7-segment LED displays, but your microcontroller only has 4 lines to select which display is active, this chip 74LS would provide a very effective method of essentially multiplying datashete selecting lines by a 4 times. Datashest when we try to implement a demultiplexer using a TTLthis is the truth table that is given in the book:. This chip is often used in demultiplexing applications, 774154 as digital clocks, LED matrices, and other graphical outputs.


(PDF) 74154 Datasheet download

So you can use a 47 kilohm resistor to pull up drops 1. This all has to do with the actual ic design.

The person who took time to answer the question will appreciate that. So theory will cover only the theory which explains the basic functionality of the working of a demultiplexor. That is, if the outputs were active high, Datasheeg gates would perform the synthesis desired.

So TTL circuitry adopted asymmetric logic levels, where ‘0’ was guaranteed to be datzsheet 0. According to the internal logic diagram on the datasheet, the G inputs are connected to a two-input AND gate with inverting inputs, whose output feeds one input of all the NAND gates that produce the outputs.

Post as a guest Name. All the other ouputs stay high. By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service. If you have some experience using BJTs you will know that Iic transistors are best used to pull a signal to 0V common emitter, with the output connected to the collector and quite weak at pulling a signal high.

I understand how it dayasheet. Sign up or log in Sign up using Google. If you wanted to generate a 1 of demultiplexer, you could use 16 s looking at the 4 least significant bits, while a single would look at the 4 most significant bits, with one ouput going to each of the other 16 s.


Download the datasheet below for a more comprehensive summary. Will someone please explain the purpose of inverting the outputs 0 through 15 as well as the use the NAND gates here?

First, the inversion of the outputs simply means that the output is active low. So is it possible that both enables are hooked to a 2-input OR gate; this is just making use of the extra pins to make 24?

Each of the 16 outputs can be connected through a resistor and then through an LED to serve as a simple 16 LED controller. But when we try datasneet implement a demultiplexer using a TTLthis is the truth table that is given in the book: However, due to the internal structure of theonly one output can be enabled at a time.

This is the image of a 1 to 16 demux. By clicking “Post Your Answer”, you acknowledge that you have read our updated terms of serviceprivacy policy and cookie policyand that your continued use of the website is subject to these policies.

National Semiconductor

Common collector, with the signal connected to the emitter, which remains at 0. There are probably two enable inputs because otherwise there would be two unused pins on the 24 pin package I don’t recall seeing 22 pin DIP packages. Email Required, but never shown. And this carried through to the dagasheet the logic was used, and designed with.

I am a new user so I didn’t know I had that power.