CD4045 21-stage counter


CD4045 belongs to the 4000 Series CMOS Logic Family of Integrated Circuits (IC’s) constructed with N- and P-channel enhancement mode transistors. CD4045 has 21-stage counter

CD4045 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.

CD4045 Features

  • Very low operating dissipation
    • <1 mW typ.) VpD 5 V, fo=1 MHz
  • Outpurt drivers with sink or source capability: 7 mA (typ.)Vpp -5V
  • Medium speed (typ: fo-25 MHz@VpD 10V
  • 100% tested for quiescent current at 20 V
  • 5-V, 10-V, and 15-V parametric ratings
  • Meets all requirements of JEDEC Tentative Standard No. 13B, Standard Specifications for Descripiton of B’ Series CMOS Devices”

CD4045 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

CD4045 Pinout Diagram

CD4045 Pin Description

Pin NoPin NameDescription
1SpSubstrate Positive
2Sn Substrate Negative
3VDDDrain Voltage
4NCNo Connection
5NC No Connection
6NC No Connection
7YThe output of the Stage counter 1
8Y+D The output of Stage counter 2
9NC No Connection
10NC No Connection
11NC No Connection
12NC No Connection
13NC No Connection
14VSSSupply Voltage
15Φ0Input 1 Of Stage Counter
16Φ1 Input 2 Of Stage Counter

CD4045 Circuit


  • Frequency counters.
  • Digital clocks.
  • Analog to digital convertors.

CD4045 Alternative Equivalent


Download CD4045 21-stage counter Datasheet from the link given below.