how to do clock duty ratio from 1/2 to 1/8

[choodzik]

hello i design a low current comparator and i need clock with duty ratio about 1/8
and i have to do it from normal ordinary clock i mean with 1/2 duty ratio

but the cicuit which will do it must take few mikroampers can you help me ??

thanks in advance

 

[spauls]

can u pls tell your problem in detail, I am not able to get completely.

 

[choodzik]

i mean clock duty ratio

my comparator needs clock with about 1/8 clock duty ratio for saving power
but in my design i only can use normal clok with 1/2 duty ratio and i have to find some circiut which will change duty ratio of my clock without changing the period.

this circiuit should take few uA mikroampers

 

[pd]

You can and two signals .First one is the original clock signal.Second one is the delayed version of the signal delayed by 3/8 of the clock period .For generating the required phase delay u have to design a DLL with 8 stages and tap ur required signal from the third delay elements output.
regards
pratap

 

[AlexWan]

For my opinion, if you don't want to use analog block, you have to ask your backend team to finish this requirement.

Before your clock root, generate a new clock from your original clock through buf delay. Then use logic operation to generate the final clock as your thinking. When you do simulation, you can use a simple model.

But this method will be modified when period or process change.

 

[choodzik]

hmmmmmmm

finally i managed to do so using two nands and two inwerters and one cmos capasitance and it works correctly

thanks for your help

 

[pd]

Can u explain the methode u applied?