Introduction to 74HC595

Introduction to 74HC595

1. 74HC595 Pinout

• It has 16 pins in total out which eight are on left side and the remaining on the right side of the structure.
• The different function is associated with each of the pin.
• Some of the pins acts as an input to this device and receives data serially and transfer to the output pins to observe the received data.
• The pin diagram for 74HC595 is shown in the figure below:

• DS pin acts and receives the serial data.
• All of the lines with prefix Q acts as the output lines.

2. 74HC595 Pin Configuration

• In this section if the tutorial Introduction to 74HC595, I will tell you about the functions associated with each of the individual pin of 74HC595.
• All of the associated functions are describes in the table given below.

3. Functioning Diagarm

• The proper functional diagram of the shift register 74HC595 is shown in the figure below.

• From the above figure you can see that SHCP, master reset (MR) and the input DS are connected to 8 stage shift register.
• Pin number 12 i.e. STCP is connected to 8 bit storage register.
• The output enable (OE) is connected to 3 state outputs.

4. 74HC595 Functional Description

•  In this section of the tutorial Introduction to 74HC595, I will tell you about the functions of each line of the 8 bit shift register 74HC595.
• Complete description of the functions of 74HC595 is given in the table shown below.

5. 74HC595 Timing Diagram

• The arrow in the upward direction shows the rising edge of the each wave either received or applied.
• The shape of the signals applied and received and their relation with each other is shown in the figure below.

5. 74HC595 Logic Diagram

• The logic diagram for 74HC595 8 bit shift register is shown in the figure below.

• You can see that there are 8 different stages from 0 to 7 and latches are there in the logic diagram of 74HC595.
• Output enable (OE) and master reset (MR) are connected to latches with an inverted sign usually known as bubble.

6. 74HC595 Current/Voltage Rating

• The current, power and voltage rating along with their values and system international units are shown in the table given below.
• The values of operating temperature and storage temperature are also shown in the figure below.

7. 74HC595 Proteus Simulation

• I have a Proteus simulation for continuous control of the different LED's using 74HC595.
• The screenshot of the simulation is shown in the figure below.

• The complete Arduino source code is shown below.
• You need to just upload .hex file of this code into the Arduino of Proteus and run the simulation.

int RCLK = 5;
int SER = 6;
int SRCLK = 7;

#define TotalIC 1
#define TotalICPins TotalIC * 8

boolean Data[TotalICPins];

void setup()
{
  pinMode(SER, OUTPUT);
  pinMode(RCLK, OUTPUT);
  pinMode(SRCLK, OUTPUT);

  ClearBuffer();
}              


void loop()
{
   for(int i = TotalICPins - 1; i >=  0; i--)
   {
      Data[i] = HIGH;
      UpdateData();
      delay(300);
      ClearBuffer();
   }

   for(int i = 1;i < TotalICPins - 1;  i++)
   {
      Data[i] = HIGH;
      UpdateData();
      delay(300);
      ClearBuffer();
   }
   
}

• The running form of the above simulation is shown in the GIF below.

• You can download the complete simulation as well as the complete Arduino source code, here by clicking on the button below.

Proteus Simulation & Arduino Code

• Just download .rar file, extract it and enjoy the complete package having both Arduino source code as well as Proteus simulation.