Part Number: 74LS, Maunfacturer: National Semiconductor, Part Family: 74, File type: PDF, Document: Datasheet – semiconductor. 74LS SN74LSD. ACTIVE. SOIC. D. Green (RoHS. & no Sb/Br) . Reproduction of significant portions of TI information in TI data sheets is. Multiplexers & Demultiplexers are available at Mouser Electronics. Mouser offers inventory, pricing, & datasheets for Texas Instruments 74LS Encoders, .
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Need help with circuit — 74ls decoder and 74ls multiplexer. Mar 23, 1.
Mar 23, 11 0. I was browsing for an electronics project and came by to this.
The schematic still lacks something. To be more precise, my goal for this project is to somehow interface the circuit using a parallel cable and connecting the 8 data pins to the multiplexer ic. Then I’ll create a program from Microprocessor using 774ls157 language. Mar 23, 2. I probably need to use the 8 data pins of a parallel cable and to create the respective program in assembly language.
Mar 23, 3. Aug 1, 7, 2, You don’t say what it is you want to do. Note that the circuit you linked actually needs 9 signals to operate, and is overly complex in my opinion. If you want to display a 2-digit number using data lines out of a microcontroller, there are several ways to do this. Some of them are: You can do that without the multiplexing circuit shown.
Two displays, two decoders each with 7 resistors8 data lines four to eachand you’re done. You can move part of the multiplexing task to your software and use only 6 signals from the uC. Two displays, one with one set of seven resistors, two transistors as digit drivers.
Mar 23, 4. Oct 27, 6, 1, Mar 23, 5. Mar 23, 6. Just so you guys know, I have literally zero knowledge in creating my own schematics. What we’ve been doing in school is datasueet our professor gives out a schematic and then we replicate the schematic in Dayasheet and then create the hardware using pcbs.
Mar 23, 7. It needs 9 signals because there are 9 external signals on the schematic: The way the circuit works is that the computer or microcontroller or Arduino or whatever puts out the BCD values of two numbers, A and B.
These sit at the inputs of the multiplexer. Then the controlling system toggles the Data Delect signal. This signal tells the multiplexer which number, A or B, to present at its outputs, and it tells the demultiplexer which digit to drive.
(PDF) 74LS157 Datasheet download
Note that there are a couple of electrical errors in the schematic, and it will not function as drawn. Given that the two number values are static at the multiplexer input, the circuit is overly complex. It would actually be easier and cheaper to directly drive two decoders as in suggestion 1 above.
Since that option is no longer an option, we move on. Your initial question about how to generate the data select signal indicates that you don’t fully understand how this circuit works, or why it should be used. I can design a better replacement, but that’s your job.
Once you understand how this one “works” and what is wrong with it, that will guide an alternative design. Mar 24, 8. Ok datasneet for the help!
I know it’s my job so I’ll somehow figure this out. Do you have any more ideas that could use 8 data lines? If not, good day then.
74LS datasheet, Pinout ,application circuits Quad 2-Input Data Selector/Multiplexer
Mar 24, 9. Does it have to be 8 data lines?
It is possible to do this with 5 lines, but you’ll have better control over the display with 6. Mar 24, Mar 25, Ok so I think I’ll go with this idea.
A 4 bit binary adder circuit. Whenever there is a carry, the LED lights up. After 9, the 7 segment doesn’t display A,B,C,etc. Only one digit output. So are there other bcd to 7 segment ICs that will properly display the hexadecimal output? And how can I make this display 2 digit outputs?
74LS Datasheet pdf – QUADRUPLE 2-LINE TO 1-LINE DATA SELECTORS/MULTIPLEXERS – Texas Instruments
Dec 29, 1, But I dont think you have it in multisim. It is able to display directly from the outputs of ‘ to 0-F in 7 segment format. Not sure if you have it in your sim You can use two 4-bit adders in series to make an 8-bit adder. This would drive two digits. The BCD parts would be perfect if you can find them. The Motorola MC datasheet has the connection details. Also, each switch input to the chips needs a 10K pulldown resistor.
Quad 2-Input Data Selector/Multiplexer
Need Help with circuit and components!! Posted by 1ronman in forum: Need help with circuit Posted by karaandnick in forum: Need help with circuit!
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