Hi pupils! Welcome to another article on integrated circuits. We have been studying different ICs in detail and today the topic is 74LS164. It is another important family member of the 74xx series of ICs and is widely used in different types of digital devices because it is a serial-in parallel-out shift register.
In this article, we’ll discuss the 74LS154 in detail. We’ll start with the introduction and after that, I’ll share a detailed datasheet with you that will help you understand the workings and basic structure of this app. After that, I’ll discuss the working principle and share a simple project of this IC in proteus. Moreover, I'll share the measurement of the dimensions of this IC and in the end, there will be the details of applications for 74LS164. This article has all the basic information about this IC and let’s start our discussion with its introduction
It is a synchronous reset register that takes the serial input but can process and represent the data in the parallel output.
It belongs to the 74LS family; therefore, it is a low-power Schottky TTL logic circuit.
It has an asynchronous clear.
It is a 14-pin dual inline package (DIP) and sometimes the package is a small outline integrated circuit (SOIC).
It acts differently in the situation. At the low logic level, it follows the logic given next:
It may inhibit the entry of new data
At the next clock pulse, it resets the flip-flops to the low level
As a result, it has complete control over the incoming data.
At the high logic level, any input enables other inputs and this determines the start of the first flip-flop.
This is one of the most simple and versatile registers; therefore, it has multiple applications in different fields where digital circuits are used.
The information about the datasheet of this IC will help you understand the basic information in detail.
The 14-pin package has a specific pin configuration. Each PIN has a specific name according to its function. This can be understood with the following connection diagram
It has the outputs on both sides of the IC.
A cut on the ground pin side indicates the right direction of the pin combination.
It has two serial inputs.
The details of the above diagram will be clear with the help of the following table:
Pin No |
Pin Name |
Description |
1 |
A |
Data Input |
2 |
B |
Data Input |
3 |
Q0 |
Output pin |
4 |
Q1 |
Output pin |
5 |
Q2 |
Output pin |
6 |
Q3 |
Output pin |
7 |
GND |
Ground Pin |
8 |
CP |
Clock Pulse Input |
9 |
MR’ |
Active Low Master Reset |
10 |
Q4 |
Output pin |
11 |
Q5 |
Output pin |
12 |
Q6 |
Output pin |
13 |
Q7 |
Output pin |
14 |
Vcc |
Chip Supply Voltage |
Table 1: 74LS164 pinout configuration
The combination of the inputs in this IC results in different conditions. Here is the detailed table for this:
CP |
DSM |
MR |
Operation |
Description |
Additional Notes |
↓ |
X |
X |
Clear (Asynchronous Master Reset) |
It immediately clears all flip-flops to 0, regardless of clock or other inputs. |
Overrides all other operations. |
↑ |
X |
H |
Hold (No Change) |
Maintains the current state of the register. |
It is useful for pausing data transfer or holding a specific value. |
↑ |
L |
X |
Load Parallel Data |
Loads the parallel data inputs (A-H) into the register. |
It occurs on the next rising clock edge. |
↑ |
H |
H |
Shift Right (Serial Input) |
Shifts data one position to the right, with new data entering at the serial input (SER). |
Occurs on each rising clock edge. |
Table 2: 74LS164 Sequential Logic Circuit Combination
This can be understood with the following information:
CP (Clock Pulse) = It controls the timing of data transfer and operations.
DSM (Data Strobe Master) = It enables parallel data loading when low.
MR (Master Reset)= It asynchronously clears the register when low.
X = It is the "don't care" condition, which means the input can be either high or low without affecting the operation.
↑ = It represents a rising clock edge.
↓= It represents a falling clock edge.
The internal structure of any IC is much more complex than the connection diagram because ICs consist of a combination of different logic gates. Here is the logic diagram that displays the internal structure of the 74LS164:
Figure 3: 74LS164 Logic Diagram
Here, you can see how the basic logic gates combine to form the 74LS164.
The operations and the clock shifting of the 74LS164 are understood with the following diagram.
Figure 4: 75LS164 Timing Diagram
This is a general representation of the timing diagram that can be understood with the help of the following points:
The rising edge clock pulse signal (CP) results in the shifting operation of the pulse.
When the parallel load phase is applied to the parallel inputs, it affects the content of the shift register.
The master reset signal clears the active low transition and clears the shift register asynchronously.
If you want to know more details about the datasheet for 74LS164, then you can visit this:
The general representation of the circuit diagram is important to understand when you are using it in practical work. Here is the diagram that clearly specifies the working and pin connections of this IC.
Figure 5: Circuit diagram of 74LS164
The 74LS164 has a pin named MR, which is a low active input master reset pin. The output of this pin remains in a low state until the state of the circuit is low. In such conditions, the values on the input do not affect its state.
The MR pin is also referred to as the reset or clear mode pin.
The procedure of the circuit’s working is completed only when the output of the MR pin is set high.
This IC has two serial input pins for all the functions. These pins are responsible for the versatility of this IC.
In order to ignore any unintentional input signal, any unused input is set to high.
In the event that the clock transition is set from low to high, the data in the IC is moved to one place on the right. The AND operation of the input pins A and B determines the new value of the right-most bit, Q0.
Before ordering or testing this IC, a good practice is to learn how it works in the simulator. I am presenting a simple circuit of the 74LS164 IC in Porteus ISIS. The following are its details:
74LS164 IC
LEDs
SW-SPDR (switch)
Power terminal
Ground terminal
Clock pulse
Open the Proteus software.
Go to the pick library “P” option and choose the first three components one by one by typing their names and double-clicking on them.
Arrange these components on the screen.
Connect the components using the wire connections.
Go to terminal mode from the left side of the screen and attach ground, power, and clock terminals on the required sites.
The circuit should look like the following image:
Figure 6: Proteus Simulation of 74LA123
The connections must be created cleanly and clearly to ensure the right output.
Click on the play button presented on the left side of the screen to start the simulation.
Once the project is complete, you will see the following points:
The circuit does not show any output on the LEDs when the circuit is played. At this point, the LM317 does not get any input.
Once the negative input is provided to the switch, the LEDs start showing the output one after the other. This shows the logic HIGH on the bits after the regular interval.
Figure 7: output of 64LS164 circuit with a switch on the negative side
Now, use the switch to provide the positive bit to the circuit, and the output on the LEDs will be shifted to the right.
Figure 8: 74LS164 output when the plus side of the switch is on
As a result, the LEDs will show the LOW output one after the other and in the end, it will show the LOW output at every LED.
If you want to test the circuit by yourself, download the simulation from the link given here:
74LS164 working Porteus Simulation
The basic features and specifications of the 74LS164 are given next:
Characteristic |
Value |
Description |
Operating Voltage |
3V - 18V |
Range of input voltage for proper operation |
Maximum Supply Voltage |
5.25 V |
The absolute maximum voltage that can be applied to the device |
Propagation Delay Time |
25 ns |
Time for a signal to travel through the device's internal circuitry |
Maximum Clock Frequency |
36 MHz |
The highest clock rate at which the device can reliably function |
Operating Temperature Range |
0°C to +70°C |
Environmental temperature range for reliable operation |
Clock Buffering |
Fully Buffered |
Internal clock buffering for improved signal integrity and noise immunity |
Available Packages |
16-pin PDIP, GDIP, and PDSO |
Different physical package options for PCB mounting |
Logic Family |
74LS (Low-power Schottky) |
A specific logic family with tradeoffs in speed and power consumption |
Power Consumption |
(Typical) 75 mW |
Average power is drawn during operation |
Output Current |
15 mA |
The maximum current that can be sourced or sunk by the outputs |
Fan-out |
10 LS-TTL Loads |
The number of logic gates that can be driven by a single output |
Input Threshold Voltage |
1.3 V |
Minimum input voltage level to reliably recognize a logic high |
Table 3: Features and Specifications of 74LS164
Just like other integrated circuits, the physical dimensions of the 74LS164 are also described in two units:
The metric dimensions are those in which the units used are the following:
Millimetres (mm)
Centimeters (cm)
Meters
Kilograms
Seconds
On the other hand, imperial units are those where the used units are the following:
Inches
Feet
Pounds
The dimensions of 74LS164 are given in the table:
Dimension |
Metric (mm) |
Imperial (inches) |
Length |
19.30 ± 0.30 |
0.760 ± 0.012 |
Width |
6.35 ± 0.25 |
0.250 ± 0.010 |
Height |
3.94 ± 0.25 |
0.155 ± 0.010 |
Pin spacing |
2.54 ± 0.10 |
0.100 ± 0.004 |
Table 4: Physical dimensions of the 74LS164
As mentioned before, the 74LS164 is a versatile register IC. It has multiple applications mentioned here:
The feature of the 74LS164 to store memory temporarily is useful in applications like the arithmetic logic register. Moreover, on the same device, it also shifts the data within the arithmetic logic register. Here, the main purpose of using 74LS164 is to use serial or parallel data handling.
The sequence generator requires the shifting and storing of the bit values. This can easily be done with the 74LS164 IC.
74LS164 is part of a large digital circuit. In digital up and down counters, this IC has applications because it has a sequential counting feature and when clock pulses are applied, it can decrement the values accordingly.
The basic feature of this IC is the serial to parallel output conversion. This feature makes it ideal for the circuit such as parallel to the serial output and vice versa.
So, in this article, we study the 74LS164 register IC in detail. We started with the basic introduction and then saw the details of the datasheet. There, we saw circuit diagrams, truth tables, logical circuits, and other related features to understand the basics of this IC. After that, we learned the working principle so that we could use it in the proteus simulation. Once we saw the results of the simulation, we studied the features and specifications of this IC, and in the end, we saw the applications of 74LS164. I hope we covered all the points but if something is missing, you can suggest it in the comment section.
Hello students! Welcome to another tutorial on the integrated circuit in Proteus. Different integrated circuits are revolutionizing the electronic world and today we are discussing one of them. The core topic of this tutorial is the 74LS160 IC in the proteus but before that, we’ll understand the basics of this IC.
In this article, we’ll start learning the 74LS160 from scratch. We’ll see its introduction and datasheet in detail. You will see the truth table, logic diagram, and pinouts of this IC in detail, and then we’ll move on to the basic features of this IC. You will see the simulation of 74LS160 in Proteus and in the end, we’ll go through some important applications of this IC. Let’s move towards the introduction first.
Figure 1: Top view of 74LS160 IC
74LS160 is an integrated circuit (IC) that is used as a counter in digital electronics.
It is a 4-bit binary synchronous counting device.
It belongs to the family of the 74xx series of ICs and the letters LS indicate that these belong to the low-power Schottky series.
This IC is made with the transistor transistor logic (TTL) technology.
It is an edge-triggered and cascadable MSI building block for multiple purposes, such as counting, memory addressing, frequency division, etc.
Moreover, it is widely used in digital circuits because it is presettable; that is, it can be used as the initial counter.
A feature of this series is that it has an asynchronous Master Reset (Clear) input that acts as an independent input, and the cock or other inputs do not control it.
Before using any digital IC, it is important to understand its structure and datasheet. The details given below will help you understand the workings of this IC:
The 74LS160 is 16 in IC and here is its connection diagram, DIP:
Figure 2: Pinout configuration of 74LS160
You can see that each pin has a name and number associated with it. The details of each pin can be seen in the table given next:
Symbol |
Name |
Description |
PE |
Parallel Enable (Active LOW) Input |
Enables parallel loading of data into the counter |
P0–P3 |
Parallel Inputs |
Four parallel data inputs for loading the counter |
CEP |
Count Enable Parallel Input |
Enables counting when asserted (Active LOW) |
CET |
Count Enable Trickle Input |
Enables counting when asserted (Active LOW) |
CP |
Clock (Active HIGH Going Edge) Input |
Clock input for synchronous counting (Active on rising edge) |
MR |
Master Reset (Active LOW) Input |
Resets the counter to 0 when asserted (Active LOW) |
SR |
Synchronous Reset (Active LOW) Input |
Resets the counter synchronously (Active LOW) |
Q0–Q3 |
Parallel Outputs (Note b) |
Four parallel binary outputs represent the count |
TC |
Terminal Count Output (Note b) |
Indicates when the counter reaches its maximum count |
Table 1: Pinout configuration of 74LS160
In different cases, when the 74LS160 is shown with the logic symbol given here:
Figure 3: Logic Symbol of 74LS160
Here, pin 16 is used for the power input and pin 8 is used as the ground. The names and numbers of the pins are the same as given before in the form of the table.
The truth table of this IC will help you understand the output of 74LS160 when the specific combination of inputs is fed into it. But before this, it is important to understand the following denotations in the table:
X = Don't-care condition
L = Logic low or ground
H = Logic high or positive voltage
CEP = Count Enable Parallel Input
CET = Count Enable Trickle Input
CP = Clock (Active HIGH Going Edge) Input
MR = Master Reset (Active LOW) Input
SR = Synchronous Reset (Active LOW) Input
CEP |
CET |
CP |
MR |
SR |
Mode |
X |
X |
X |
H |
X |
Load data (P0-P3) |
L |
H |
X |
X |
X |
Enable parallel load |
H |
L |
X |
X |
X |
Enable count (normal) |
H |
H |
L |
X |
X |
Enable count (trickle) |
H |
H |
H |
L |
X |
Reset (clear) counter |
H |
H |
H |
H |
L |
Synchronous reset |
H |
H |
H |
H |
H |
Load data (P0-P3) |
Table 2: Truth table of 74LS160
The working principle of 74LS160 can be understood with the help of some important points about its internal structure. The basis of its working principle is to understand that when the clock pulse is applied to the 74LS160, it responds to it and counts the binary values. Here are the important points to understand this:
Since the beginning, we have been mentioning that it is a 4-bit counter. It means it can count from 0000 to 1111 in binary numbers.
As with other integrated circuits, the counter responds to the clock pulse applied to its clock input. The rise in the clock input stimulates the counter operations.
The parallel load inputs are denoted by P0 to P3. The counter allows the parallel loading of the data when the appropriate pattern of signals is applied at the input pins.
Cascading is the process in which two or more integrated circuits are connected with each other in such a way that the output of one circuit becomes the input of the other. This is done to enhance the working ability of the system or is crucial when higher calculations are required using the counter.
The 74LS160 allows the cascading process. In this case, the ripple carry output (RCO) is connected with the clock input of the next counter.
Now, it is better to understand how to create the circuit of this IC in the Porteus simulator before using it in the circuit. Here is the way to create the circuit:
74LS160
Switch
LED
Clock
Ground
Power
Fire up the proteus software.
Choose the first three components from the list given above.
Place them in the working area to create the circuit.
Now, go to terminal mode from the left side of the screen and choose ground terminal. Place it in the respected area.
Repeat the above step for the power terminal.
Now go to generation mode and choose the Dclock.
Place the clock on pin 2 of IC.
Connect the component through the connecting wires.
The circuit must look like the image given here:
Figure 4: Proteus Circuit for 74LS160
The circuit is now ready to work. Click on the play button to start the working of the circuit.
The switches are used to provide the input signal to the circuit. When the switch is on, the input signal to the respective pin is HIGH, otherwise low.
At the start, the LEDs are working in a particular manner that the output is on all the pins in a particular pattern.
Figure 4: Changing the input of the 74LS160 circuit
Change the input through the switches and you will observe the change in the output.
You will observe a change in the values of output when the signal on the input signals is changed.
Figure 5: Getting the output of the 74LS160 Circuit simulation
The inputs and outputs are the same as given in the truth table.
If you want to have the design of the Proteus project I am using, then you can download it through the link given next:
Proteus simulation for the basic working of 74LS160
The 74LS160 has different modes and studying all of these will help you to understand the features and specifications.
On reaching the clock edge, a pulse propagates that stimulates the counter to work.
The master-slave FF is the pulse that triggers the master-slave flip-flop structure of this IC. The state of the internal logic circuit is changed according to the structure of the IC. The details of these inputs are given in the table given before.
The logic gates of flip-flops determine the output of the IC. Usually, the output depends on the following factors:
The current state of the pins
Previous inputs of pins
Feedback connections.
In some versions, 75LS160 has the decade working, which means these can provide values between 0 and 9.
The state of the master flip flop is transferred to the corresponding slave flip flop after some time. This is done to provide a stable and more synchronized output.
During the processing, the low signals on the load input activate the logic path of the IC.
All the values in the data inputs are transferred directly to the respective flip-flops.
The process of overriding the current counter bypasses the internal counter logic. It also sets the counter’s desired initial values and this is done by presetting the counter.
The reset pin is the active low pin, which means the output is reset when this pin has a zero value.
The clearing of the flip flop is the situation when all the FFs are forced to reset their values, no matter what the values on their inputs or what the values of the clock are.
The logic gates in the structure of the integrated circuit determine the internal structure of the flip flops. These are particularly useful for the transition from 1001 to 0000, which is 9 to 0 in the decimal numbers.
When the transition of the carry-out goes high, it indicates that the count cycle is complete.
The carryout pulse can be used in the cascading counter to enhance the working ability of the circuit using 74LS160.
If you want to use the 74LS160 in your circuits, you must know the physical dimensions of this IC. There are two basic units to measure the physical dimensions of devices like ICs:
In the metric package, only metric units are used to represent the calculations. The following are some of the basic units in this system:
Millimetres (mm)
Centimeters (cm)
Meters
Kilograms
Seconds
Usually, in the representation of the physical dimensions of the ICs, like 74LS160, millimeters are used for metric packages.
The imperial units are also known as the British imperial units. The popular units in the imperial packages are:
Inches
Feet
Pounds
The physical dimensions of the ICs in the imperial package are mostly inches. Here is the table that clearly shows the physical calculations of the 74LS160 IC:
Dimension |
Metric (mm) |
Imperial (inches) |
Length |
19.30 ± 0.30 |
0.760 ± 0.012 |
Width |
6.35 ± 0.25 |
0.250 ± 0.010 |
Height |
3.94 ± 0.25 |
0.155 ± 0.010 |
Pin spacing |
2.54 ± 0.10 |
0.100 ± 0.004 |
Table 3: Physical dimensions of 74LS160
The following are some prime applications where the 74LS160 is extensively used:
The most common example of the application of this IC is to use it as a digital counter. When the clock pulse is applied to this IC, it represents the binary counting values. This is not only used as it is but usually other logic gates are combined with it to get the complex calculator to work.
The frequency divider is the circuit that is designed to determine the value of frequency after dividing it by the power of 2. This circuit is incomplete without the 74LS160 IC.
This IC is incorporated into the time circuits, where its main job is to generate a time delay. Moreover, it also triggers specific events based on certain conditions. These conditions are set during the design process of the circuit.
In the sequential logic, the 74LS160 is used as the counter. The output of this IC is used as the input of some other devices and this creates the basis of the sequential logic circuits.
Signal processing is an important field where complex circuits are used. This IC is used in devices for signal processing where counting and timing functions are required.
Hence, today, we have seen the details of the 74LS160 Integrated Circuit. We started with the basic introduction of this IC and understood the structure and output of every pin through its datasheet. Through the logic diagram, logic circuit, truth table, and the pinouts of this IC we understood the details of its functionalities. Moreover, we saw its basic features and mode of operation. The physical dimensions of this IC made clear the domains of its usage in different circuits. We saw the simulation of the 74LS160 in the proteus and in the end, we shed light on different applications where the 74LS160 plays a vital role. I hope you have understood all the information but if you feel something missing or have any questions, you can ask us.