What exactly does common cathode mean in terms of a seven segment display. Im trying to display numbers on a 7-segment that i placed on a breadboard . Im using a 7493 binary counter through a 7447 bcd to seven segment display decoder, but all im getting is weird readings on the 7-segment. How do i wire this?? Does the counter have to be negative edge or use a diff decoder??

 

Common cathode means all the leds have their cathodes connected to each other and it comes out of the 7-seg as 1 single pin.

To see the connections of a 7447 see the datasheet:
http://www.fe.up.pt/~victorm/DataSheet/TTL/7446_47A.pdf

As you will see in the datasheet 7447 is designed to drive common anode displays, wich is why you get strange readings

use 7448 to drive common cathodes, or buy common anodes to go with your 7447's

 

Thanks for that info
Also, If the 7-Seg display has 2 common cathode pins, can i just wire them together and connect them to ground or just wire both to ground?

 

normally, they are internally connected to each other, so connect one of them, or both, it doesn't mather.

 

Thanks Alot, you completely answered my question :lol: