TTL and Counting!

W

watzmann

New Member

• Apr 8, 2008

• #1

i need to desin a counter using a T flip flip , could you tell me please which TTL ic contains 3 or 4 T Flip-Flops ?

 

P

petrv

New Member

• Apr 8, 2008

• #2

You can use 74LS74 there are (only) 2 independent D flip-flops. There is also 74LS175 which has 4 D flip-flops but all their clock inputs are connected together so if you down't want that you cannot use this one. But there are also ready-made counter ICs for example 74LS93 or 74LS161/163, or 74LS193 ...

 

W

watzmann

New Member

• Apr 8, 2008

• #3

but i need T flip flop , not D flip flop....

i cannot use the ready made ones , because this for a tutorial purpose.

 

P

petrv

New Member

• Apr 8, 2008

• #4

So you can use a JK flip flop and connect J and K together to get the "T" input ... 74LS73, 74LS76 ....

 

W

watzmann

New Member

• Apr 8, 2008

• #5

ah , i'll try this

 

W

watzmann

New Member

• Apr 8, 2008

• #6

please i have a question , while i'm designing the counter , i faced the following problem ,

i have just three T flip flops with three outputs , if i need to display the output on 7 segment so i used 7447 seven segment driver ,

but i have A,B,C,D....

where to connect the final one D ........because i just have A,B,C

 

ericgibbs

Well-Known Member

Most Helpful Member

• Apr 8, 2008

• #7

watzmann said:

please i have a question , while i'm designing the counter , i faced the following problem ,

i have just three T flip flops with three outputs , if i need to display the output on 7 segment so i used 7447 seven segment driver ,

but i have A,B,C,D....

where to connect the final one D ........because i just have A,B,C

Click to expand...

Connect 'D' to 0volts.

 

Papabravo

Well-Known Member

• Apr 8, 2008

• #8

There is no such thing as a dedicated T-flip-flop. It is a pedagogical abstraction. As has already been mentioned you can construct one from a JK flip-flop which you seemed OK with. It may be worth mentioning that you can do the same thing with a D-flip-flop which you dismissed out of hand. To make a "T" out of a "D" you connect "Q-BAR" to "D" and clock away.

I'm really curious about why this happened. Did you really think there was such a thing as a T-flip-flop?