Connection for clock distribution
 

John,
How about a miniature stereo phono plug? These have 2 signal circuits plus a
ground. They're common, they're available in many PCB configurations, and
they're cheap.

Joe
W3JDR


"John Wilkinson" wrote in message
...
Hi,
I have a 1MHz clock that I need to disribute to several boards. I am using
RS485 drivers and receivers to do this, along with twisted screened
cable.

The question is that I need a 2 pole pcb connector that is screened.
Does anyone know of such a beast?

Thanks,
John.

Connection for clock distribution
 

Problem with a phono-plug and a clock signal is that you will get reflection
back -- probably much better off with a BNC or SMA connector.

"W3JDR" wrote in message
news:NXhVf.9224$6%2.4606@trnddc08...
John,
How about a miniature stereo phono plug? These have 2 signal circuits plus
a
ground. They're common, they're available in many PCB configurations, and
they're cheap.

Joe
W3JDR


"John Wilkinson" wrote in message
...
Hi,
I have a 1MHz clock that I need to disribute to several boards. I am
using
RS485 drivers and receivers to do this, along with twisted screened
cable.

The question is that I need a 2 pole pcb connector that is screened.
Does anyone know of such a beast?

Thanks,
John.

Connection for clock distribution
 

Hi,
I have a 1MHz clock that I need to disribute to several boards. I am using
RS485 drivers and receivers to do this, along with twisted screened cable.

The question is that I need a 2 pole pcb connector that is screened.
Does anyone know of such a beast?

Thanks,
John.

Connection for clock distribution
 

The author said it was RS-485. This is a 2-wire differential signalling
system. He also wants to use a shield. Hence the need for 3 circuits. I
doubt that reflections will play any part in the performance, especially
considering that he's using twisted-pair for the signals. This is how CAT5
RS-485 distribution works.

Besides, he's talking about a1 MHz presumably steady-state square-wave clock
and presumably short board-to-board connection lengths.


Joe
W3JDR


"jack" wrote in message
...
Problem with a phono-plug and a clock signal is that you will get
reflection
back -- probably much better off with a BNC or SMA connector.

"W3JDR" wrote in message
news:NXhVf.9224$6%2.4606@trnddc08...
John,
How about a miniature stereo phono plug? These have 2 signal circuits
plus
a
ground. They're common, they're available in many PCB configurations, and
they're cheap.

Joe
W3JDR


"John Wilkinson" wrote in message
...
Hi,
I have a 1MHz clock that I need to disribute to several boards. I am
using
RS485 drivers and receivers to do this, along with twisted screened
cable.

The question is that I need a 2 pole pcb connector that is screened.
Does anyone know of such a beast?

Thanks,
John.

Connection for clock distribution
 

On Sun, 26 Mar 2006 21:19:01 GMT, W3JDR wrote:

The author said it was RS-485. This is a 2-wire differential signalling
system. He also wants to use a shield. Hence the need for 3 circuits. I
doubt that reflections will play any part in the performance, especially
considering that he's using twisted-pair for the signals. This is how CAT5
RS-485 distribution works.

Besides, he's talking about a1 MHz presumably steady-state square-wave clock
and presumably short board-to-board connection lengths.


Joe
W3JDR


"jack" wrote in message
...
Problem with a phono-plug and a clock signal is that you will get
reflection
back -- probably much better off with a BNC or SMA connector.

"W3JDR" wrote in message
news:NXhVf.9224$6%2.4606@trnddc08...
John,
How about a miniature stereo phono plug? These have 2 signal circuits
plus
a
ground. They're common, they're available in many PCB configurations, and
they're cheap.

Joe
W3JDR


"John Wilkinson" wrote in message
...
Hi,
I have a 1MHz clock that I need to disribute to several boards. I am
using
RS485 drivers and receivers to do this, along with twisted screened
cable.

The question is that I need a 2 pole pcb connector that is screened.
Does anyone know of such a beast?

Thanks,
John.





HI,
Yes this is a differential signale, so needs 2 connections plus ground for
the shield.

I have looked for these stereo phono plugs, but to no avail, any idea who
stocks them, RS/Farnell numbers.

Thanks,
John.

Connection for clock distribution
 

John,

Over here we'd just run down to the nearest Radio Shack store, or if we had
to mail-order them we'd go to Digikey (www.digikey.com) or Mouser
www.mouser.com). Here is a link to a digikey catalog page that shows the
different types they carry:
http://dkc3.digikey.com/PDF/T061/0304.pdf

Also, here is a link to a Digikey search page from which you can narrow your
search down to a specific type and stock number:
http://www.digikey.com/scripts/DkSea...S&Cat=32440884

If you follow the above link to a specific connector, you'll eventually get
to a page that has the manufacturer's web sites and datasheet information.
This might help you at least pick a connector type, then go to the
manufacturer's web page and find out who stocks the part in your area.

Joe
W3JDR


"John Wilkinson" wrote in message
...
On Sun, 26 Mar 2006 21:19:01 GMT, W3JDR wrote:

The author said it was RS-485. This is a 2-wire differential signalling
system. He also wants to use a shield. Hence the need for 3 circuits. I
doubt that reflections will play any part in the performance, especially
considering that he's using twisted-pair for the signals. This is how
CAT5
RS-485 distribution works.

Besides, he's talking about a1 MHz presumably steady-state square-wave
clock
and presumably short board-to-board connection lengths.


Joe
W3JDR


"jack" wrote in message
...
Problem with a phono-plug and a clock signal is that you will get
reflection
back -- probably much better off with a BNC or SMA connector.

"W3JDR" wrote in message
news:NXhVf.9224$6%2.4606@trnddc08...
John,
How about a miniature stereo phono plug? These have 2 signal circuits
plus
a
ground. They're common, they're available in many PCB configurations,
and
they're cheap.

Joe
W3JDR


"John Wilkinson" wrote in message
...
Hi,
I have a 1MHz clock that I need to disribute to several boards. I am
using
RS485 drivers and receivers to do this, along with twisted screened
cable.

The question is that I need a 2 pole pcb connector that is screened.
Does anyone know of such a beast?

Thanks,
John.





HI,
Yes this is a differential signale, so needs 2 connections plus ground for
the shield.

I have looked for these stereo phono plugs, but to no avail, any idea who
stocks them, RS/Farnell numbers.

Thanks,
John.

Connection for clock distribution
 

Hi

I would use a USB connector and cable. These contain two (possibly
three) twisted pair with a shield around them. They are controlled to
93 ohms differential impedance, and do not have significant reflections
below 1 Ghz when terminated properly. They are cheap and plentiful,
and available in a variety of sizes for PCB mount.

Mouser sells a good assortment--I usually go for the 'B' size for PCBs.
I use these for an RF differential probe I designed, with good
results.

There are also lines of shielded telephone connectors and cable
available. For a 1 Mhz clock these would do well, and do not have as
low an impedance, which might be easier for your 485 drivers to work
into.

Regards,
Glenn