How to generate a tracking pulse with nano-seconds precision in a low-cost way

Hi there,

I believe it is easy to use a high-end digital oscillator these days to
generate a tracking pulse with a few nanoseconds delay compared to the
reference pulse. However, I am thinking about the possibility to
implement the task in a different way, a lower-cost way.

Last month I designed a small circuit to generate the reference pulse
sequence at 35.42MHz with DW9255 (35.42M central freq plus max 300ns
GDR)at board. Now I want to add a few more components to the board so I
can generate a tracking pulse sequence as well. I want the tracking
pulse sequence is only a few nano-seconds delay compared to the
inputing pulse sequence, and I want the delay between them is as stable
as possible. For example, 10 nanoseconds delay with 1 nanosecond drms.
In other word, I only care about the time difference stability between
these two sequences.

I am thinking about any possibilties at this moment and their costs as
well, for example, a positive feedback circuit. Could anybody please
provide me some ideas to implement this task? Lower cost will be
better.

Thanks in advance.

Johnson

Hello Johnson,

> Last month I designed a small circuit to generate the reference pulse
> sequence at 35.42MHz with DW9255 (35.42M central freq plus max 300ns
> GDR)at board. Now I want to add a few more components to the board so I
> can generate a tracking pulse sequence as well. I want the tracking
> pulse sequence is only a few nano-seconds delay compared to the
> inputing pulse sequence, and I want the delay between them is as stable
> as possible. For example, 10 nanoseconds delay with 1 nanosecond drms.
> In other word, I only care about the time difference stability between
> these two sequences.
> 

Usually this is done with LC delay lines. Several mfgs, in North America 
for example:
http://www.belfuse.com/

You can, of course, roll your own. The trick for a jitter free ride is 
to not introduce too much low pass characteristic, maintain a nice flat 
group delay and follow it up with a low noise RF amp. I usually follow 
up with a discrete amp, BFS17 or womething like that. Or a fast buffer 
if digital.

Regards, Joerg

http://www.analogconsultants.com

Johnson wrote:

> Hi there,
> 
> I believe it is easy to use a high-end digital oscillator these days to
> generate a tracking pulse with a few nanoseconds delay compared to the
> reference pulse. However, I am thinking about the possibility to
> implement the task in a different way, a lower-cost way.
> 
> Last month I designed a small circuit to generate the reference pulse
> sequence at 35.42MHz with DW9255 (35.42M central freq plus max 300ns
> GDR)at board. Now I want to add a few more components to the board so I
> can generate a tracking pulse sequence as well. I want the tracking
> pulse sequence is only a few nano-seconds delay compared to the
> inputing pulse sequence, and I want the delay between them is as stable
> as possible. For example, 10 nanoseconds delay with 1 nanosecond drms.
> In other word, I only care about the time difference stability between
> these two sequences.
> 
> I am thinking about any possibilties at this moment and their costs as
> well, for example, a positive feedback circuit. Could anybody please
> provide me some ideas to implement this task? Lower cost will be
> better.

There'd be the 100EP196. Not exactly cheap, especially
considering the translators.

Rene
-- 
Ing.Buero R.Tschaggelar - http://www.ibrtses.com
& commercial newsgroups - http://www.talkto.net

Hello Rene,
> 
> There'd be the 100EP196. Not exactly cheap, especially
> considering the translators.
> 

There are alos some other silicon delay chips, or programmable delay 
lines. I have removed chip delay circuits from a few product designs 
because they were expensive and caused too much noise.

Regards, Joerg

http://www.analogconsultants.com