HCFBE I have suffered one displeasing feature most times useful of this counter, When the clock advances, decade counting also advances from 0 to 9 then 0 to 9 and so on. On reaching "9" again returns to "0" and so on. But the problem is that when we power up the circuit again, the counter starts from out "9" not from initial "0" when detecting first LOW-to-HIGH clock edge. In most applications this is a good feature. But look up other attachment. That is five LOW-to-HIGH clock ring edges detected, then when goes to "6" out the counter automatically reset by the arrangement shown in schematic.
|Published (Last):||21 February 2017|
|PDF File Size:||5.39 Mb|
|ePub File Size:||2.25 Mb|
|Price:||Free* [*Free Regsitration Required]|
Where to use CD IC The IC CD is used for counting applications, it has the capability to turn on 10 outputs sequentially in a pre-defined time and reset the count or hold it when required. It also has the capability to indicate the status of counting using Carry pin.
We have 10 output pins ranging from Q0 to Q9, these pins can be connected to any load but we are using LEDs here as shown in the circuit below. This IC will increment the count from 0 to 9 Q0 to Q9 each time it senses a high pulse from the clock pin pin The output changes sequentially from Q0 to Q9 for every high pulse from the Clock pin, but this sequence can be interrupted by two pins.
They are the Clock Enable pin 13 and Reset pin 15 pins. Similarly, if the reset pin is made high. The count will reset itself back to Q0 and will stay there until Q0 is made low again. We have another pin called the carry out pin 12th pin , this pin will stay low 0V by default. But when the IC completes counting up to 10, the pin will go high and will remain high till it counts till 5, when its 5 it will go down 0V and turn on again when it reaches The timing diagram of the IC indicating the state of Output pins and Carry pin for every high pulse signal is shown below.
(hcf4017be) decade counter with 10 decoded outputs
Decade counter 4017