N Datasheet, N PDF, N Data sheet, N manual, N pdf, N, datenblatt, Electronics N, alldatasheet, free, datasheet. Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue any product or service without notice, and advise . 3. Ordering information. 74HC; 74HCT 4-to line decoder/ demultiplexer. Rev. 7 — 29 February Product data sheet. Table 1. Ordering .
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It will indicate which output you need to toggle on the Arduino in order to drive the appropriate output of the Demultiplexer. Rather than providing only a single enable, both pins are used. June 14th, 0 Comments. Use 4 Arduino pins for 16 outputs! June 18th, 1 Comment.
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? Sign up using Facebook. My first question is more important Diego July 26, at 5: There are probably two enable inputs because otherwise there would be two unused pins on the 24 pin package I don’t recall ratasheet 22 pin DIP packages. As for the NAND gates, there is a function being implemented in which the gates are there to realize it.
Its purpose is to take a Serial signal and convert it to a parallel one. This leads to possible outputs ranging from to on the 4 pins. WhatRoughBeast 49k 2 28 Since the ouputs are active low, NAND gates do the job.
According to the internal logic diagram on the datasheet, the G inputs are connected to a two-input Datashete gate with inverting inputs, whose output feeds one input of all the NAND gates that produce the outputs.
I was wondering if you can control multiple 74hc with the 74lsn. A demultiplexer is a great way to allow you to use more output pins for your Arduino. The active-low output is just how the design for that specific decoder was carried out – there is also active-high varieties.
This section will describe daasheet pin you will need to use. Post as a guest Name.
Datasheet(PDF) – National Semiconductor (TI)
Hi Sean, No, that would not work. The active-low enable inputs allow cascading of demultiplexers over many bits. If you have any questions about the implementation, feel free to post them below or on the forums. Will someone please explain the purpose of inverting the outputs 0 through 15 as well as the use the NAND gates here?
EEEnthusiast May 12, at 8: Sign up using 74154nn and Password. First, the inversion of the outputs simply means that the output is active low.
Circuits Intégrés Logiques TTL
June 30th, 0 Comments. June 23rd, 0 Comments.
Home Questions Tags Users Unanswered. You can upvote more than one answer. Leave A Comment Cancel reply Comment. And why are there 2 of them, you ask? 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.
Sign up or log in Sign up using Google. Here is the truth table from the datasheet: That is, for an input ofthe 0 output is selected, and it is driven low. Keep in mind that my video showcases the hardware implementation of the IC before jumping into the Arduino Serial datzsheet Parallel implementation.
If you want 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. That is, if the outputs were active high, OR gates would perform the synthesis desired. The person who took time to answer the question will appreciate that.
Serial to Parallel Demultiplexer.