4-line to line Decoders/demultiplexers. Each or these 4-line-toline decoders utilizes TTL circuitry to decode four binary-coded inputs into one of. MOS technology. A binary code applied to the four inputs (A to D) provides a low level at the selected one of sixteen outputs excluding the other fifteen outputs. SNN .. of significant portions of TI information in TI data books or data sheets is permissible only if reproduction is without alteration.
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The LED can be chosen at random by the datzsheet of the 4 line selector inputs. My first question is more important Low Level Input Current. Home Questions Tags Users Unanswered. 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 you selecting lines by a 4 times.
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.
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Sign up or log in Sign up using Google. Note 3 I CC is measured with all outputs open and all inputs grounded. Y Typical propagation delay.
Datasheet, PDF – Alldatasheet
However, due to the internal structure of theonly one output can be enabled at a time.
74154 Datasheet PDF
That is, if the outputs were active high, OR gates would perform the synthesis desired. Y Performs the demultiplexing function by distributing data. If Military Aerospace specified devices are required.
I am a new user so I didn’t know I had that power. Y Alternate Military Aerospace device is avail. 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.
National Semiconductor – datasheet pdf
Will someone please explain the purpose of inverting the outputs 0 through 15 as well as the use the NAND gates here? Operating Free Air Temperature Range. Each or these 4-line-toline decoders utilizes TTL circuit. And why are there 2 of them, you ask? WhatRoughBeast 49k 2 28 Y Decodes 4 binary-coded inputs into one of 16 mutually.
If you wanted to generate dagasheet 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.
Note 2 Not more than one output should be shorted at a time. These demultiplexers are ideally suited for implementing high-performance memory decoders. Office Distributors for availability and specifications. As for the NAND gates, there is a function being implemented in which the gates are there to realize it.
High Level Output Datashee. 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.
The active-low output is just how the design for that specific decoder was carried out – there is also active-high varieties. Understand, this is a typical example of application, not it’s sole purpose. Absolute Maximum Ratings Note.
Since the ouputs are active low, NAND gates do the job. Y High fan-out low-impedance totem-pole outputs. Sign up using Facebook. Low Level Output Current.
That is, for an input ofthe 0 output is selected, and it is driven low. Email Required, but never shown.