Hello everyone,
I've tried implementing a circuit with that output, but I get a '0' logic. This may be due to my lack of knowledge of LTSPICE.
I would appreciate any help
thx

 

The "A" devices in LTspice work on 0-1V by default. You have set the parameters for only one of the three devices. You need to set the parameters for the other two. Hint: configure the first one and clone it. The first FF "A1" is not toggling because the D input is fixed at 0 volts

 

The "A" devices in LTspice work on 0-1V by default. You have set the parameters for only one of the three devices. You need to set the parameters for the other two. Hint: configure the first one and clone it. The first FF "A1" is not toggling because the D input is fixed at 0 volts

Even after I've set the parameters it looks like the DFF doesn't work.
May you know which parameters I need to change to make it work?

 

This example file from the collection of @Bordodynov may have some clues for you. I think the fault is in your design. The feedback from A2 keeps A1 from ever having a non-zero value. Try isolating one of your flip-flops to see if it will toggle. Then revise your design for the behavior with unspecified initial conditions. Next delay the start of the common clock and have a RESET signal that will put all three flip-flops into the desired initial condition.

 

I've revised your original to show the RESET function and how the feedback from A2 prevents A1 from being anything but zero.
ETA: Feeding the Q output back to the D input does not have a tendency to work well unless you are trying to make a shift register.

 

Hello everyone,
I've tried implementing a circuit with that output, but I get a '0' logic. This may be due to my lack of knowledge of LTSPICE.
I would appreciate any help
thx
View attachment 341056

Its best to use uniform timings when your starting out until you fully understand LTspice digital devices.
I used a .param statement to set common parameters to be used in all the devices. Then I applied the parameter names to each device attributes.

Also, in real a DFF, the pre and clear pins would'nt be left disconnected, but in these "raw" digital devices, the ground connections can cause logic issues. If they are unused, its better to leave them unconnected.

 

Its best to use uniform timings when your starting out until you fully understand LTspice digital devices.
I used a .param statement to set common parameters to be used in all the devices. Then I applied the parameter names to each device attributes.

Also, in real a DFF, the pre and clear pins would'nt be left disconnected, but in these "raw" digital devices, the ground connections can cause logic issues. If they are unused, its better to leave them unconnected.

View attachment 341086

Tnx a lot!