ATA signal integrity over dual PCBs

Hi,

I'm wondering if there will be severe signal integrity issues if I use
a 2mm pitch 2x22 socket and header combination to connect 2 PCBs
together, assuming I still adhere to the impedance of the ATA signals
on the PCB and keeping the trace lengths within ATA specs? In total
there will be 3 connectors - a pin header on the ATA host side PCB, a
pin socket on the ATA device side PCB, and another pin socket on the
ATA device side PCB that connects to the actual HDD.

"galapogos" <goister@gmail.com> wrote in message news:1174985194.270284.157990@p77g2000hsh.googlegr oups.com
> Hi,
>
> I'm wondering if there will be severe signal integrity issues if I use
> a 2mm pitch 2x22 socket and header combination to connect 2 PCBs
> together, assuming I still adhere to the impedance of the ATA signals
> on the PCB and keeping the trace lengths within ATA specs? In total
> there will be 3 connectors - a pin header on the ATA host side PCB, a
> pin socket on the ATA device side PCB, and another pin socket on the
> ATA device side PCB that connects to the actual HDD.

What do you need specs for if you can't expect them to "work".

Ever heard of laptops and laptop harddrives?

On Mar 28, 2:08 am, "Folkert Rienstra" <see_reply...@myweb.nl> wrote:
> "galapogos" <gois...@gmail.com> wrote in messagenews:1174985194.270284.157990@p77g2000hsh.g ooglegroups.com
> > Hi,
>
> > I'm wondering if there will be severe signal integrity issues if I use
> > a 2mm pitch 2x22 socket and header combination to connect 2 PCBs
> > together, assuming I still adhere to the impedance of the ATA signals
> > on the PCB and keeping the trace lengths within ATA specs? In total
> > there will be 3 connectors - a pin header on the ATA host side PCB, a
> > pin socket on the ATA device side PCB, and another pin socket on the
> > ATA device side PCB that connects to the actual HDD.
>
> What do you need specs for if you can't expect them to "work".
>
> Ever heard of laptops and laptop harddrives?

Well, I just just worried that the extra connectors would cause
undesirable reflections/ringing and other related SI issues.

Previously galapogos <goister@gmail.com> wrote:
> On Mar 28, 2:08 am, "Folkert Rienstra" <see_reply...@myweb.nl> wrote:
>> "galapogos" <gois...@gmail.com> wrote in messagenews:1174985194.270284.157990@p77g2000hsh.g ooglegroups.com
>> > Hi,
>>
>> > I'm wondering if there will be severe signal integrity issues if I use
>> > a 2mm pitch 2x22 socket and header combination to connect 2 PCBs
>> > together, assuming I still adhere to the impedance of the ATA signals
>> > on the PCB and keeping the trace lengths within ATA specs? In total
>> > there will be 3 connectors - a pin header on the ATA host side PCB, a
>> > pin socket on the ATA device side PCB, and another pin socket on the
>> > ATA device side PCB that connects to the actual HDD.
>>
>> What do you need specs for if you can't expect them to "work".
>>
>> Ever heard of laptops and laptop harddrives?

> Well, I just just worried that the extra connectors would cause
> undesirable reflections/ringing and other related SI issues.

I agree that that could be an issue. But typically, if
this is an 3.5" to 2.5" adapter, it works. In fact these
things work when connected to an ata cable, so there should be
some margin.

Arno

On Mar 28, 1:08 pm, Arno Wagner <m...@privacy.net> wrote:
> Previously galapogos <gois...@gmail.com> wrote:
> > On Mar 28, 2:08 am, "Folkert Rienstra" <see_reply...@myweb.nl> wrote:
> >> "galapogos" <gois...@gmail.com> wrote in messagenews:1174985194.270284.157990@p77g2000hsh.g ooglegroups.com
> >> > Hi,
>
> >> > I'm wondering if there will be severe signal integrity issues if I use
> >> > a 2mm pitch 2x22 socket and header combination to connect 2 PCBs
> >> > together, assuming I still adhere to the impedance of the ATA signals
> >> > on the PCB and keeping the trace lengths within ATA specs? In total
> >> > there will be 3 connectors - a pin header on the ATA host side PCB, a
> >> > pin socket on the ATA device side PCB, and another pin socket on the
> >> > ATA device side PCB that connects to the actual HDD.
>
> >> What do you need specs for if you can't expect them to "work".
>
> >> Ever heard of laptops and laptop harddrives?
> > Well, I just just worried that the extra connectors would cause
> > undesirable reflections/ringing and other related SI issues.
>
> I agree that that could be an issue. But typically, if
> this is an 3.5" to 2.5" adapter, it works. In fact these
> things work when connected to an ata cable, so there should be
> some margin.
>
> Arno

You make a good point. I hadn't thought about the adapters. My
application wouldn't have a cable, but will add a 2 connectors, so I
guess it should work. I wonder how "clean" the ATA signals are after
the adapter...