A D Flip-flop problem

[z0123]

hello everyone.
I have a problem about D Flip-flop.
What kind of D Flip-flop can work at GHz.
Please tell me.
Thank you.

 

[barry]

Look at ECL parts

 

[goldsmith]

hello everyone.
I have a problem about D Flip-flop.
What kind of D Flip-flop can work at GHz.
Please tell me.
Thank you.

Hi z0123
You can simply refer to the website of some famous manufacturers and see what they have in their productions !
or perhaps asking their technical support guys ! ( for example texas instrument or fairchild semiconductor or national semiconductor or .... etc )
Best Wishes
Goldsmith

 

[SIDDHARTHA HAZRA]

Normal CMOS F/F can work in GHz range make sure the ft for the MOSFET used in that technology is very high. Typically for 5GHz kind of result, devices with ft > 30-40GHz should work.
(Though its not a thumb rule .... just from experience).
Any thing higher than that you can look into CML architectures ... just Google it up ... Hope it will help

 

[barry]

Normal CMOS F/F can work in GHz range make sure the ft for the MOSFET used in that technology is very high. Typically for 5GHz kind of result, devices with ft > 30-40GHz should work.
(Though its not a thumb rule .... just from experience).
Any thing higher than that you can look into CML architectures ... just Google it up ... Hope it will help

First of all, I'm not sure why this question is in the Analog forum, and second, I think the OP is looking to BUY a FF, not design one. There are no OTS CMOS FF's that I'm aware of that will run anywhere near 1GHz.

 

[z0123]

hello everyone.
I have a problem about D Flip-flop.
What kind of D Flip-flop can work at GHz.
Please tell me.
Thank you.

I want to design a D Flip-flop .

 

[barry]

Maybe you should have said that in your original post.

 

[goldsmith]

I want to design a D Flip-flop .

Hi again

I highly suggest you to ask your questions clearly to avoid misunderstanding and confusion !

So , you wanna deign , now what's your problem ? what we can do for you ?


Best Luck
Goldsmith

 

[z0123]

hello everyone.
I have a problem about D Flip-flop.
What kind of D Flip-flop can work at GHz.
Please tell me.
Thank you.

I want to design a DFF for phase detection.
I used TSPC DFF to do that. but output is wrong.

the DFF clock catch low but output q is high.
this is why I want to design a high frequency DFF.
Thanks

 

[SIDDHARTHA HAZRA]

First of all, I'm not sure why this question is in the Analog forum, and second, I think the OP is looking to BUY a FF, not design one. There are no OTS CMOS FF's that I'm aware of that will run anywhere near 1GHz.

Hi barry,

I agree that the post should not have been in the analog forum.
and CMOS F/F does work in >1GHz range for technology below 130nm where MOSFET have ft > 30-40GHz ....

- - - Updated - - -

I want to design a DFF for phase detection.
I used TSPC DFF to do that. but output is wrong.
**broken link removed**
the DFF clock catch low but output q is high.
this is why I want to design a high frequency DFF.
Thanks

Hi z0123,

I dont know why I am unable to open your attachment ... can you check that once ...
Any ways for high speed digital ckts in CMOS domain you have to look at the MOS ft numbers first and then decide whether you can design it in your desired range.
Refer to my first post ..... hope it will help ..

 

[z0123]

Hi barry,

I agree that the post should not have been in the analog forum.
and CMOS F/F does work in >1GHz range for technology below 130nm where MOSFET have ft > 30-40GHz ....

- - - Updated - - -



Hi z0123,

I dont know why I am unable to open your attachment ... can you check that once ...
Any ways for high speed digital ckts in CMOS domain you have to look at the MOS ft numbers first and then decide whether you can design it in your desired range.
Refer to my first post ..... hope it will help ..

sorry my bad

 

[SIDDHARTHA HAZRA]

Hi z0123,

Is it possible to show the architecture ..... and can you verify the setup time for your flop.
As it is clearly visible that the Q is always high and the input In is changing just before clock edge. If your setup is not sufficient then the Q wont trip.

You can try two things:
1) Your clock is 2GHz so characterize your flop and see whether it can at all work in 2GHz or not. Find 1/(t_setup + t_clk_to_Q) will give you the operating frequency for your flop (You can read more on flop characterization ... you will find material over net).
2) Just try to use a lower frequency clock (1MHz or so) and give more time between input change and clock edge and see whether it works or not