Simplest way to generate 2ch clock 180 degree phase shift with 40% duty cycle 500kHz

Irving

Joined Jan 30, 2016
3,843
Here's my suggestion.
NAND gates are CD4093B.
I could have made a T-FF with the remaining CD4093B's (whole circuit using only one chip) but I think the CD4013 will provide better symmetry.
Uses two chips including the CD4013B. Probably run better at 12v.

View attachment 259040
Not wanting to be overly critical, but I don't see the requested 10% dead time in that trace. It should look more like:

1643467513106.png

You need to gate the outputs of the FlipFlop with the 80% wide 1MHz incoming clock (or its inverse if is 20% wide as here) eg:

1643474300986.png

Edit: fixed missing attachment...
 
Last edited:

eetech00

Joined Jun 8, 2013
3,858
Not wanting to be overly critical, but I don't see the requested 10% dead time in that trace. It should look more like:
You need to gate the outputs of the FlipFlop with the 80% wide 1MHz incoming clock (or its inverse if is 20% wide as here) eg:
That's a way to do it...but I didn't see a request from the TS for dead time.
 

Irving

Joined Jan 30, 2016
3,843
I understood it differently.
Two clocks, 180 degrees out of phase, each with 40% duty cycle.
If the TS stated "for a mosfet driver", then dead time would be implied, to me anyway...
Assuming the 40% (0.8uS) is in the 1st half of each 2uS interval on each phase then the description forces a 0.2uS deadtime between phases. There was no statement regarding "mosfet driver" and not all drivers generate dead-time anyway. But your solution doesn't generate 40% duty cycle on both phases, it generates 40% + its inverse, although I accept there is some ambiguity in the request.
 

eetech00

Joined Jun 8, 2013
3,858
There was no statement regarding "mosfet driver" and not all drivers generate dead-time anyway.
I know....but it would helped.

But your solution doesn't generate 40% duty cycle on both phases, it generates 40% + its inverse, although I accept there is some ambiguity in the request.
It generates 40% duty on each phase, which is what I intended, but i agree, not relative to each output waveform.

We really need to hear from the TS...
 
Last edited:

drjohsmith

Joined Dec 13, 2021
852
I might have missed this
but Is this by any chance for a switch mode power supply controller ?

Any reason your not using an off the shelf SMPS controller ?
 
Top