How to Use the CD4035 Shift Register?

What is a CD4035 Shift Register?

The CD4035 is a protean binary 4- bit stationary shift register with a resemblant input and periodical output. It’s extensively used in colorful operations including data storehouse, data transfer and digital logic circuits.

How to Use the CD4035 Shift Register

1. Wiring the CD4035 Shift Register

The first thing you will do with an important function, after incorporating the CD4035 into your circuit, is to wire it correctly to the circuit. The chip has a total number of 16 pins, each of the other pins denoting some other function. The following are description of connecting the key pins:

  • Vcc (Pin 16) and Ground (Pin 8): Connect the Vcc pin to your power force( generally 5V or 3.3 V), also connect the Ground pin to base in your circuit.
  • Serial Data Input (Pin 2): This is the pin where you will send data one bit at a time in serial form. You should connect this pin to any output of your microcontroller, sensor, or another data source that will send the serial data.
  • Clock Input (Pin 3): The clock pin controls when bits are shifted into the register. This pin should be connected to a clock signal possibly generated by a microcontroller or external oscillator.
  • Parallel Data Outputs (Pins 6, 7, 9, and 10): The data stored in the shift register is provided by these pins in parallel. Depending on the application, you can connect them to LEDs, other logic components, or input pins of a microcontroller.
  • Reset Pin (Pin 12): This pin is used to clear the data stored in the shift register. A low signal on this pin will reset the shift register, clearing any previous data. This is useful for initializing the register before beginning data shifts.
  • Shift-Right Control (Pin 5) and Shift-Left Control (Pin 4): These legs control the shifting direction of the shift register. Typically, you can say that in most applications, you will shift data into the register using the shift- right control pin and in the correct order.

2. Loading Data into the CD4035

Once you’ve set up the connections, you can begin loading data into the shift register. To do this, you will:

  • Provide a clock signal: The CD4035 shifts data with each rising or falling edge of the clock signal. By sending a clock pulse, you will shift the data stored in the shift register. Each pulse moves the data one bit to the right, filling the parallel outputs with the appropriate bits.
  • Serial data input: The serial data is bitwise sent to the data input pin (Pin 2). For instance, where data ‘1011’ are to be stored, bits ‘1’, ‘0’, ‘1’, and ‘1’ are sent serially to the input pin, arriving one at a time at the input pin on the rising edges of the clock.
  • Clocking the data: Each time you send a clock pulse, the bits you input are shifted into the register. The first bit entered will appear on the far-left parallel output pin, and the last bit will appear on the far-right output after all shifts are completed.

3. Accessing the Parallel Output

After shifting in the data, you can read it simultaneously from the parallel output pins (Pins 6, 7, 9, and 10). These outputs will present the stored data in parallel, meaning you can access the 4-bit value all at once, making it convenient for connecting to multiple devices such as LEDs, displays, or other logic circuits. It is particularly useful in situations in which you want to control numerous components (like an array of LEDs) with only a few microcontroller pins, with each parallel output used for one bit of the data being sent.

For instance, if the data stored in the shift register is ‘1011’, then the outputs at the parallel outputs will represent this value in parallel; Pin 6 will show ‘1’, Pin 7 will show ‘0’, Pin 8 will show ‘1’, and Pin 10 will show ‘1’. These outputs can then be connected to a display or other components to visualize or use the data in your application.

4. Resetting the CD4035

At certain points, it may become desirable to first clear out the information contained in the shift register, possibly when loading new information. In order to accomplish this, the reset pin (Pin 12) must be accessed. By pulling this pin low (sending a logic “0”), the shift register will reset, clearing all the stored data and preparing it to receive new data. You can also wire this reset pin to a microcontroller or a control signal to reset the shift register when necessary.

5. Cascading Multiple Shift Registers

Whenever it proves necessary to use more than 4 bits of data, this can be done through the cascading of a number of CD4035 registers to attain further data processing capabilities. Cascading is accomplished when the serial output of a first register is connected to the serial input of the next, then the serial transfer of data down a length of shift registers occurs, thus allowing the storage and output of an increased number of bits of data. The important task is to keep the clock signals in phase, to ensure that all the shift registers clock-in synchronously to allow for data shifting along the entire length of the chain.

6. Practical Application Example

An example of actual application may arise when control of a 4×4 LED matrix is desired, using the CD4035. In this case, the parallel outputs of the shift register would be used to interface with the LED matrix, enabling the shifting of data into illuminated LEDs on said matrix. Each bit of data being shifted in would correlate with a row or column of LEDs, enabling the control of several LEDs with just a few pins from a microcontroller. Using the clock pin, you can cycle through each row or column to create dynamic lighting effects or display information.