And look how complicated is has become, compared to the circuit in post #10!

Of course.
But the TS wants to use CD4013B.

 

True.
My circuit is post #56 is also simple, requiring only 3 passive parts plus one of the two FFs in the CD4013 package, and thus doesn't necessarily need another gate package.

So here's my take on using 1/2 of the CD4013 IC as a simple debounce circuit with fast rise/fall output times to clock the toggle FF:
R2C2 provides a delay so that bounce on both the closing and opening of the PB switch (blue trace) is suppressed.
The circuit uses the CD4013 characteristic that when both PRE and CLR are high the Q output is high.

View attachment 330379

If U1A reset is tied to VDD, then U1A will never "set", So I guess I don't understand how this can work(?).

 

If U1A reset is tied to VDD, then U1A will never "set", So I guess I don't understand how this can work(?).

It will set.
As I noted in my post, it depends upon a quirk in the CD4013's logic where both outputs go high when both SET and RESET are high (below).
Thus the Q output will go high and low with the SET input, if the RESET input is held high.

 

It will set.
As I noted in my post, it depends upon a quirk in the CD4013's logic where both outputs go high when both SET and RESET are high (below).
Thus the Q output will go high and low with the SET input, if the RESET input is held high.

View attachment 330470

that’s different than the TI data sheet.

edit: oh wait…I see

 

that’s different than the TI data sheet.

Then we have dueling datasheets.
This is the one I got that table from.

That data sheet matches the behavior of my LTspice CD4013 model.

 

Then we have dueling datasheets.
This is the one I got that table from.

That data sheet matches the behavior of my LTspice CD4013 model.

right…I see now.
I’ll have to try it on bench

 

What TI data sheet shows otherwise?

 

It will set.
As I noted in my post, it depends upon a quirk in the CD4013's logic where both outputs go high when both SET and RESET are high (below).
Thus the Q output will go high and low with the SET input, if the RESET input is held high.

View attachment 330470

So...I tested this at 5v and 9v and it missed button presses sometimes (didn't toggle/not reliable).
I tested this circuit the same way I tested mine.

 

I tested this at 5v and 9v and it missed button presses sometimes (didn't toggle/not reliable).

So what exactly did the Q output of the left FF do when it "didn't toggle"?

 

I do notice that in addition to the other changes, that the 220 K resistors are now all 10K resistors. It could be useful to try that simple change in the original circuit from post #1.

 

So what exactly did the Q output of the left FF do when it "didn't toggle"?

retained the same state.

 

retained the same state.

I meant the Q output of the FF used for debounce.
Is it oscillating during the transition?
If so, a small amount of hysteresis added from the Q output, to the PRE input should eliminate that.
It can't remain in the same state unless it violates its truth-table.

 

I meant the Q output of the FF used for debounce.
Is it oscillating during the transition?
If so, a small amount of hysteresis added from the Q output, to the SET input should eliminate that.
It can't remain in the same state unless it violates its truth-table.

I didn't check with a scope.
I'm wondering if the dynamic specs have something to do with this. That is, internal rise time/prop delays are not exactly the same for both S/R inputs.

What do you propose for hysteresis?

 

What do you propose for hysteresis?

This, if needed.

 

This, if needed.

View attachment 330504

OK. Tested with 3-15v supply. I couldn't make it fail with the hysteresis modification.
U1A is debouncer, so I used U1B to complete the toggle function.
Here's the test circuit I used:

 

Tested with 3-15v supply. I couldn't make it fail with the hysteresis modification.

Great.
But you didn't look to see why the circuit without the hysteresis failed?
It would be interesting to know.

 

Great.
But you didn't look to see why the circuit without the hysteresis failed?
It would be interesting to know.

I'll test it later when I have a chance...
BTW - Nice work!

 

What is the PB model you used in LTspice?

 

What is the PB model you used in LTspice?

It is one that I made. It has adjustable bounce duration, as well as the usual parameter adjustments.

 

It is one that I made. It has adjustable bounce duration, as well as the usual parameter adjustments.

That's a very useful model.
If you could post the model and symbol files, I'd appreciate it.