CD4015 4-Stage Shift Register Serial in/Parallel Out

CD4015 IC is a static 4-stage data shifting IC consisting of two independent Shift Registers. These two shift registers provide serial input / parallel output registers. in other words, shift registers convert serial data into parallel data. The date that this CD4015 can convert is 4 bit. All inputs are protected by diodes and series resistors to protect them against static discharges. All register stages are composed of D type, master-slave flip flops with independent RESET and CLOCK inputs. It is available in 16-pin packages which include PDIP, GDIP, PDSO.

CD4015 Pinout diagram

As you can see from the pinout diagram, the CD4015 shift register IC consists of 16 pins. Blue color shows pins of register B and Green color depicts pins of shift register A.

CD4015 Pinout diagram shift register

Pin Configuration Description 

The CD4015 IC has a total of 16 pins. Each pin, its number, and description are mentioned in the table below.

Pin NumberPin NamePin Description
1Clock BClock pulse signal for shift register B
2, 11, 12, 131B, 2B, 3B, 4BOutput pins for shift register B
3, 4, 5, 101A, 2A, 3A, 4AOutput pins for shift register A
6RESET AResponsible for resetting all the outputs of a shift register A
7DATA AInput data pin for shift register A
8VssNegative power supply or ground of the circuit
14RESET BResponsible for resetting all the outputs of a shift register B
15DATA BInput data pin for shift register B
16VccPower supply voltage

Other alternative and Equivalent shift Registers: 74HC595, CD4035,, CD4014, CD4022

CD4015 Static Shift Register Features

  • Dual 4-bit IC having serial Inputs and a parallel output Shift register composed of 8 master-slave flip flops.
  • Fully static operation with a clock frequency of 8.5Mhz at 15V
  • Operating voltage range is 3V to 18V with medium speed operation
  • Consumes low power of 80uA
  • TTL compatible
  • Maximum Clock Frequency is 12Mhz at 10V

Alternative options

Where to use CD4015 IC

It is commonly used in high voltage applications as it has a wide operating voltage range. It can also be used as an I/O expander to control multiple outputs. It can be used in applications that require controlling multiple outputs in a parallel mode as it has 8 parallel outputs. Due to its large number of outputs, you can expand the I/O capability using this IC. You can use it in LED chasers and LED drivers.

How to use a CD4015 IC 

CD4015 Example circuit

The IC consists of two 4 stage shift registers. Each register has its own 4 bits input, a RESET pin, and a Clock. The clock signal is provided through a PWM signal generated through a 555 timer or any other digital IC. This is a functional block diagram of IC:

CD4015 internal functional block diagram

The pins 1 and 9 are clock inputs that provide a constant signal. It has only 1 data input pin. The data value present at this input is transferred into the first register stage on the positive edge of a clock. At each positive transition of a clock, this data is shifted over one stage. The rest pin is responsible for resetting all the output values. When this pin is HIGH, it resets output pins. The reset pin is normally connected to the ground of the circuit. The truth table showing the state of the register after the positive transition of clocks is shown in the table below.

working truth table

Example Circuits

In this example, we can use the most popular cd4015 shift register. It is a dual 4-bit shift register that you can control 4 bits on the output side using serial data it’s also called a serial-in parallel-out register. One register will have four outputs,  one data pin,  one clock pin, and one reset pin. So now let’s see an example simulation circuit part and understand how the IC actually works.
CD4015 how to use example circuit simulation in proteus
  • In this example circuit, we connect serial data 0001 to serial input pin15 (Pin D) and a clock signal to pin1.
  • We can use the Probestate of proteus to see the output from pins Q0-Q3.
  • As soon as we apply a clock signal to CD4015, data will start to shift on the output pin.
  • Because input data is 0001, 1 will appear on Q0 on the fourth edge of the positive clock cycle.

CD4015 Proteus Simulation

  • For simulation purposes, we are using logic states and logic probes of proteus. We will provide clock signal and serial data input through these logic states.
  • For simulation purposes, We will use the toggle switch to provide a positive edge. Because, switching from zero to one, will provide a positive edge, to shift register.
  • We can use the Probe state of proteus to see the output of Q0 to Q3.
  • Now let’s see proteus simulation working,
  • First makes serial data input pin logic high, that means, logic one will transfer to each stage on every positive edge of the clock cycle, Because in serial mode, data transfer bit by bit.
  • Hence, on the first positive edge, pin Q0 will become one, on the second positive edge of the clock, pin Q1 will become high, and so on.
  • After that, apply the clock signal and see the output of the shift register.  As you can see, as soon as we apply a clock signal to CD4015, data will start to shift on the output pins.
  • Now change the serial data input to logic low,
  • In the end, apply the clock signal, as you can see, logic zero appears on pin Q0 and other pins sequentially on every positive edge of the clock,


This IC has numerous applications. Some of them are:

  • It can be used in serial to parallel data conversion as it has serial input and parallel data outputs.
  • Due to its multiple outputs, it is used in LED matrix projects in which LEDs are interfaced with the outputs.
  • It can be used in cascading applications by connecting multiple IC’s of CD4015.
  • Cube Projects and High logic level controllers also use this IC
  • In communication lines for transmitting and conversion of data.

2D Diagram

two Dimensions diagram


CD4015 Datasheet

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