Connecting the input of 74ls47 to the output of another ic

Thread Starter


Joined Oct 28, 2019
I have connected a 7 segment common anode led to 7447 ic. It works fine with the switches. Now I want to connect the inputs of a 7486 ic to input A and 7432 ic to input B and then tie both the inputs C and D to ground. Will this setup work ? What resistors should I put in the inputs? I am using a 5 volt supply which outputs 1 amp current.


Joined Jan 15, 2015
There is no need for any resistors since everything is 5 volt TTL Logic. The current capabilities of your power source doesn't matter as the circuit will only draw what it requires. On the 7486 and 7432 if you have unused inputs tie them to either VCC or Ground as all unused inputs must go somewhere.