Part Number: 74LS, Maunfacturer: Motorola, Part Family: 74, File type: PDF, Document: Datasheet – semiconductor. These 8-bit shift registers feature gated serial inputs and an asynchronous clear. A low logic level at either input inhibits entry of the new data, and resets the first. It has 2N states where ‘N’ is the number of flip-flops. So here is how to make a Johnson counter using IC 74LS Here are some of the features of IC

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Propagation Delay Time, Reset to Q. Fully Buffered Clock and Serial Inputs. For example if the pin — outs 1 and 2 are permanently connected to the positive supply and the reset pin is joined to the last output of the IC pin 13then, as discussed earlier, once all the outputs become high the last pin 13 instantly resets the whole circuit, shutting the whole array of outputs, and the cycle repeats. The serial 74ls64 pin 1 and 2 of the IC has a special purpose of resetting the above procedure in an interesting pattern.

A high level input enables the other input which will then determine the state of the first flip-flop. Data at the serial inputs may be changed while the clock is high or low, but only information meeting the setup requirements will be entered clocking occurs or the ratasheet level transition of the clock input.


The gated serial inputs A and B permit complete control over incoming data as a low at either or both input s inhibits entry of the new data and resets the first flip flop to the low level at the next clock pulse. The whole output array, instead of shutting down all together, now starts receding sequentially one-next-to-the-other, until all of them are shut down to begin the cycle all over again. Setup Time, A1 or A2 to Clock. Maximum Ratings are those values beyond which damage to the device may occur.

All inputs are diode- i to minimize transmission-line effects.

Low Level Input Voltage. Introduction Through a few of my previous articles I have tried to cover the working principles of a couple of versatile ICs like the and This 8-bit shift register features gated serial inputs and an. Hopefully you will get to see another article pretty soon, which will explain the practical utility of this wonderful IC. Hold Time, Clock to A1 or A2. Not more than one output should be shorted at a time, and duration should not exceed one second.

74LS164 – 8-Bit Shift Register Ser In/Para Out

Referring to the figure on the left we see that externally it looks just like an ordinary pin dual in-line chip.

Through a few of my previous articles I dqtasheet tried to cover the working principles of a couple of versatile ICs like the and Output Short Circuit Current. Low Level Output Voltage.

Low Level Output Current.

The extreme top left pin from the printed side is the first pin in the order, and the pin just opposite to it on the other row is the last or the 14 th pin. Unlike ordinary CMOS ICs which has also been datashet in many of my previous articlesthe above ICs are equipped with many different built-in features which may be accessed or activated by just applying the appropriate logic inputs or components to their relevant pin-outs.


This opposite sequencing also takes 7l4s164 in accordance to the rising pulse of the input clocks. High Level Input Current.

Functional operation should be restricted to the Recommended Operating Conditions. High Level Output Voltage.

74LS Datasheet pdf – 8-Bit Serial In/Parallel Out Shift Register – Fairchild Semiconductor

High Level Input Voltage. Search field Part name Part description. High Level Output Current. Low Level Input Current.

How Would You Build Moving LED Signs Using IC 74LS164? Pin-Outs Explored

Now suppose if through a simple wiring pins 1 and 2 are configured in such a way that when the last pin 13 of the IC goes high while sequencing serially, it grounds the serial input 1 and 2. All diodes are 1N or 1N Similarly the IC requires only an external clock signal to make its outputs swing into action and produce interesting logic sequences. Propagation Delay Time, Clock to Q.