CD4021 8-stage Static Shift Register


CD4021 belongs to the 4000 Series CMOS Logic Family of Integrated Circuits (IC’s) constructed with N- and P-channel enhancement mode transistors. CD4021 has 8-stage Static Shift Register

CD4021 has a supply voltage range of 5V to 20V, which is much higher than any contemporary logic family. It has buffered output which improves transfer characteristics by providing very high gain. All inputs are protected against static discharge with diodes to VDD and VSS.

CD4021 Features

  • High Voltage Types (20V Rating)
  • Medium Speed Operation 12MHz (Typ.) Clock Rate at VDD-VSS = 10V
  • Fully Static Operation
  • 8 Master-Slave Flip-Flops Plus Output Buffering and Control Gating
  • 100% Tested for Quiescent Current at 20V
  • Maximum Input Current of 1µA at 18V Over Full Package Temperature Range; 100nA at 18V and +25oC
  • Noise Margin (Full Package Temperature Range)
    • 1V at VDD = 5V
    • 2V at VDD = 10V
    • 2.5V at VDD = 15V

CD4021 Specifications

Absolute Maximum Ratings

  • DC Supply Voltage Range, (VDD): -0.5V to +20V (Voltage Referenced to VSS Terminals)
  • Input Voltage Range, All Inputs: -0.5V to VDD +0.5V
  • DC Input Current, Any One Input: ±10mA
  • Operating Temperature Range: -55oC to +125oC Package Types D, F, K, H
  • Storage Temperature Range (TSTG): -65oC to +150oC
  • Lead Temperature (During Soldering): +265oC
    • At Distance 1/16 ± 1/32 Inch (1.59mm ± 0.79mm) from case for 10s Maximum

CD4021 Pinout Diagram

CD4021 Pin Description

Pin NoPin NameDescription
1PI-8Parallel Input 8 of Shift Register
2Q6The output of Shift Register 6
3Q8The output of Shift Register 8
4PI-4Parallel Input 4 of Shift Register
5PI-3Parallel Input 3 of Shift Register
6PI-2Parallel Input 2 of Shift Register
7PI-1Parallel Input 1 of Shift Register
9LATCHLatch Input
10CLKClock Signal Input
11SERIALSerial Input
12Q7The output of Shift Register 7
13PI-5Parallel Input 5 of Shift Register
14PI-6Parallel Input 6 of Shift Register
15PI-7Parallel Input 7 of Shift Register
16VDDDrain Supply

CD4021 Circuit


  • Parallel Input/Serial Output Data Queueing
  • Parallel to Serial Data Conversion
  • General Purpose Register

CD4021 Alternative Equivalent

CD4006, CD4015

Download CD4021 8-stage Static Shift Register Datasheet from the link given below.