This display driver circuit shows how a Seven Segment Display is driving with the help of the 5 stage Johnson decade counter IC CD4033.The IC has counter and decoder in one package. It converts the Johnson codes into Seven Segment Decoder output to drive the common cathode display. The display shows the counts in the form of numerical display.
The display driver circuit is powered from a 9 volt DC supply and the outputs of IC are connected to the Common Cathode Seven Segment display LT 543. The IC counts continuously up to 9 if the Clock Enable, Strobe and Reset pins are grounded. The cycle repeats till the Reset pin gets a High pulse. The input of CD 4033 is a sensitive Schmitt trigger and readily accepts positive to negative transition pulses to starts the counting.
The counter advances and the signals are available at the outputs as decoded signals which can drive the numerical display. CD 4033 can be Cascaded to connect many displays to count 100, 1000 etc. If the Carry Out pin 5 of one IC is connected to the Clock Input pin 1 of the second IC, counter continues and the second IC starts counting when the first IC completes 9 counts. In such a way many ICs can be cascaded.