Hej
has anybody used the AD9954 DDS ? i have some design quistions:
Where can i by a 400MHz precion clock source.

Coubling of the output DAC. I will try to copy the EVB9954 from analog. any
other ideas.

best regards


--
Frank Mikkelsen

University of Aarhus
Institute of Physics & Astronomi
Nymunkegade, Bygn. 520, room 432
DK-8000 AArhus C
Denmark

Phone +45 89423799 or +45 89423795
Fax: +45 89423794

In article , says...
Hej
has anybody used the AD9954 DDS ? i have some design quistions:
Where can i by a 400MHz precion clock source.


I imagine the AD9954 has an internal clock multiplier like its
predecessors in the AD985x family. Doesn't it?

-- jm

------------------------------------------------------
http://www.qsl.net/ke5fx
Note: My E-mail address has been altered to avoid spam
------------------------------------------------------

In article , says...
Hej
has anybody used the AD9954 DDS ? i have some design quistions:
Where can i by a 400MHz precion clock source.


I imagine the AD9954 has an internal clock multiplier like its
predecessors in the AD985x family. Doesn't it?

-- jm

------------------------------------------------------
http://www.qsl.net/ke5fx
Note: My E-mail address has been altered to avoid spam
------------------------------------------------------

"scharkalvin" skrev i en meddelelse
...
John Miles wrote:
In article , says...

Hej
has anybody used the AD9954 DDS ? i have some design quistions:
Where can i by a 400MHz precion clock source.



I imagine the AD9954 has an internal clock multiplier like its
predecessors in the AD985x family. Doesn't it?

-- jm

------------------------------------------------------
http://www.qsl.net/ke5fx
Note: My E-mail address has been altered to avoid spam
------------------------------------------------------

The AD9954 has a clock multiplier, and only needs a 20mhz clock
to drive it.

If anybody tries using one of these and makes up some circuit boards
let me know (before I try and wire mine dead bug style!)


I am working on a 2 layer PCB layout on a AD9954 board, but i am off for 2
weeks from to day so it suppose I will start test i in the end off august.
If somone are interested you can have a copy of SCH and PCB (protel format).

Best regars
Frank

"scharkalvin" skrev i en meddelelse
...
John Miles wrote:
In article , says...

Hej
has anybody used the AD9954 DDS ? i have some design quistions:
Where can i by a 400MHz precion clock source.



I imagine the AD9954 has an internal clock multiplier like its
predecessors in the AD985x family. Doesn't it?

-- jm

------------------------------------------------------
http://www.qsl.net/ke5fx
Note: My E-mail address has been altered to avoid spam
------------------------------------------------------

The AD9954 has a clock multiplier, and only needs a 20mhz clock
to drive it.

If anybody tries using one of these and makes up some circuit boards
let me know (before I try and wire mine dead bug style!)


I am working on a 2 layer PCB layout on a AD9954 board, but i am off for 2
weeks from to day so it suppose I will start test i in the end off august.
If somone are interested you can have a copy of SCH and PCB (protel format).

Best regars
Frank

Richard Hosking wrote:
I have asked for samples and I would be keen to do just this. However it
seems I am not an important enough customer
No doubt they will be coming out sometime soon

Richard

scharkalvin wrote in message
...

John Miles wrote:

In article , says...


Hej
has anybody used the AD9954 DDS ? i have some design quistions:
Where can i by a 400MHz precion clock source.



I imagine the AD9954 has an internal clock multiplier like its
predecessors in the AD985x family. Doesn't it?

-- jm

------------------------------------------------------
http://www.qsl.net/ke5fx
Note: My E-mail address has been altered to avoid spam
------------------------------------------------------

The AD9954 has a clock multiplier, and only needs a 20mhz clock
to drive it.

If anybody tries using one of these and makes up some circuit boards
let me know (before I try and wire mine dead bug style!)






Analog Devices will send out samples to just about anybody.
Go to their website and sign up for their monthly mailings, each
month they will send you a bingo card good for samples on up to 6 devices.
You can also request a sample of almost any part on the web site.
You might have to make up a 'bogus' company name at your home
QTH, but they don't really care. I requested a sample of the 9954 DDS,
it was mailed to me at my employers QTH. They ask you about
how many devices your company might purchase, but I just filled out
that it was for a 'future project' and 'no plans at this time'. They
didn't care and I got the sample in a week after faxing the bingo card.

AD is a VERY friendly company to get samples from.

Richard Hosking wrote:
I have asked for samples and I would be keen to do just this. However it
seems I am not an important enough customer
No doubt they will be coming out sometime soon

Richard

scharkalvin wrote in message
...

John Miles wrote:

In article , says...


Hej
has anybody used the AD9954 DDS ? i have some design quistions:
Where can i by a 400MHz precion clock source.



I imagine the AD9954 has an internal clock multiplier like its
predecessors in the AD985x family. Doesn't it?

-- jm

------------------------------------------------------
http://www.qsl.net/ke5fx
Note: My E-mail address has been altered to avoid spam
------------------------------------------------------

The AD9954 has a clock multiplier, and only needs a 20mhz clock
to drive it.

If anybody tries using one of these and makes up some circuit boards
let me know (before I try and wire mine dead bug style!)






Analog Devices will send out samples to just about anybody.
Go to their website and sign up for their monthly mailings, each
month they will send you a bingo card good for samples on up to 6 devices.
You can also request a sample of almost any part on the web site.
You might have to make up a 'bogus' company name at your home
QTH, but they don't really care. I requested a sample of the 9954 DDS,
it was mailed to me at my employers QTH. They ask you about
how many devices your company might purchase, but I just filled out
that it was for a 'future project' and 'no plans at this time'. They
didn't care and I got the sample in a week after faxing the bingo card.

AD is a VERY friendly company to get samples from.

scharkalvin wrote in
Analog Devices will send out samples to just about anybody.
Go to their website and sign up for their monthly mailings, each
month they will send you a bingo card good for samples on up to 6
devices. You can also request a sample of almost any part on the web
site. You might have to make up a 'bogus' company name at your home
QTH, but they don't really care. I requested a sample of the 9954 DDS,
it was mailed to me at my employers QTH. They ask you about
how many devices your company might purchase, but I just filled out
that it was for a 'future project' and 'no plans at this time'. They
didn't care and I got the sample in a week after faxing the bingo card.

AD is a VERY friendly company to get samples from.

I fully agree !!

Sam

scharkalvin wrote in
Analog Devices will send out samples to just about anybody.
Go to their website and sign up for their monthly mailings, each
month they will send you a bingo card good for samples on up to 6
devices. You can also request a sample of almost any part on the web
site. You might have to make up a 'bogus' company name at your home
QTH, but they don't really care. I requested a sample of the 9954 DDS,
it was mailed to me at my employers QTH. They ask you about
how many devices your company might purchase, but I just filled out
that it was for a 'future project' and 'no plans at this time'. They
didn't care and I got the sample in a week after faxing the bingo card.

AD is a VERY friendly company to get samples from.

I fully agree !!

Sam

wrote in message
...

Yes the 995x has a 4 to 20 multiplyer, but this increase the jitter on
the
output frequnce, therefore i prefere an 400MHz precition osc. if it is
possible to find it.

One way would be to have a VCO and simple 8-pin PLL I guess clocking the
chip ?

Your going to be hard pushed to find an XTAL block with a 400MHz output.

Some of the older Pentium mother boards used to use an XTAL and a chip to
generate the main hundred-odd MHz clock, not sure what the chips where
though.

I've used such multiplier chips to go from 10 to 60 MHz, for example. Look
carefully at the jitter specs. You won't like them.



During his talk on the Software Defined Radio at the recent Central States
VHF Conference, Gerry Youngblood mentioned that they avoid programming the
9954 to certain frequencies in order to reduce the worst spurs.

Those operating frequencies are achieved by slight changes in the software
and setting the 9954 to a "good" nearby frequency.

No details were given and I didn't get around to asking for the details.
Does AD give hints?