NEED help on ULTRA LOW jitter amplification

Thread Starter

abforce

Joined Nov 14, 2013
19
Hello Gurus:

I want to amplify a pair of LVPECL signals to -1,+1 volte. They are generated by CDCLVP1102 with about 5ps jitter. I used a subtractor scheme built by a THS4215D. Power supply is +-5 volte.

Now I got a square as I want but with a jitter being about 10 ns. Is there anyway to reduce this jitter?

I want the LVPECL signals being amplified, or , being compared to be a square wave with as low jitter as possible. I think comperators can do the same job but the delay is annoying and I don't have idea how well they can perform.

Thanks for all kinks of help and if you have something to ask, I will reply you with my best effort. If it's not tonight, it must be tomorrow.
 

crutschow

Joined Mar 14, 2008
29,828
Yes, I have an interest but I haven't come up with a good solution to your problem. If a high speed op amp won't work, I'm not sure what will. Perhaps this will give you some ideas.
 

Thread Starter

abforce

Joined Nov 14, 2013
19
Yes, I have an interest but I haven't come up with a good solution to your problem. If a high speed op amp won't work, I'm not sure what will. Perhaps this will give you some ideas.
Thank you for you advise! I think it's a quite interesting suggestion! I saved the datasheet and it will be a backup solution for me now. In fact I am only a green hand and I think there should be some 'know how' points to improve the performance and I just don't know them and let the OPAMP perform not as well as it could be.
 

Thread Starter

abforce

Joined Nov 14, 2013
19
What is your application?

You are not likely to achieve ps additive jitter with an op-amp - it's just too slow.

A couple of low jitter devices that may help:

http://www.analog.com/en/rfif-components/timing-ics-clocks/adclk914/products/product.html

http://www.analog.com/en/rfif-components/timing-ics-clocks/adclk846/products/product.html
Thank you! I see the devices and they have really low jitter. I am building a trigger that follows a LVPECL signal while delivers a single end ±1 signal as out put. It will drive a timing system. The requirement is just to be fast and low jitter. So I think delay for those devices is a problem in my case.
 

Tesla23

Joined May 10, 2009
510
Thank you! I see the devices and they have really low jitter. I am building a trigger that follows a LVPECL signal while delivers a single end ±1 signal as out put. It will drive a timing system. The requirement is just to be fast and low jitter. So I think delay for those devices is a problem in my case.
Now I really don't understand! The ADCLK914 has a delay of around 160ps, whereas the THS4215D takes 2ns to change from -1V to 1V. The ADCLK914 has a bandwidth around 7.5GHz, the THS4215D has a bandwidth of 350MHz. If 160ps of delay is a problem, then the THS4215D is not the answer. What sort of delay can you tolerate?
 

russ_hensel

Joined Jan 11, 2009
825
I am not very knowledgeable in this stuff but I think there may be a confusion between jitter and delay. As I understand it jitter is random variation in timing, delay is just delay. Perfectly repeatable delay would have no jitter. for ADCLK846 the delaly is 2 ns but jitter seems to be below 100 fs. I may have this wrong.
 

Thread Starter

abforce

Joined Nov 14, 2013
19
I am not very knowledgeable in this stuff but I think there may be a confusion between jitter and delay. As I understand it jitter is random variation in timing, delay is just delay. Perfectly repeatable delay would have no jitter. for ADCLK846 the delaly is 2 ns but jitter seems to be below 100 fs. I may have this wrong.
I agree with you. Jitter is the issue I want to solve and delay is not the price I want to pay, or say, if not necessary. That's the reason why I chose to use an Op-Amp at first.
 
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