FC-AL connector question

Jim McGrath jmcgrath at qntm.com
Thu Aug 3 12:01:22 PDT 1995

        Reply to:   RE>FC-AL connector question

Any power specification is always a requirement placed on the power
supply provider (i.e. host system) not the device.  Drives may or may not
use the 3 v supply - just like they may or may not use the 5 v and 12 v
supplies (note that 2.5" drives generally only use 5 v, and ignore the 12 v).

Host implementators may not supply 3.3 v, but in that case they will not be
able to use certain drives (a native 3.3 v supply to the drive results in
drive cost).  Since the whole point of a standard is to allow users to mix and
match products from various vendors, not supplying the 3.3v would seem to
defeat the purpose of being FC SCA compliant.  I would strongly advise anyone
designing a new enclosure to put in the 3.3v - if you don't you will be
the market for you product and adding system costs (the cost adder per drive
easily outweighs the cost of putting 3.3v in the enclosure).

(note - SSA also has 3.3v, and if we could we would put in in parallel SCSI -
the requirement is driven by the need of drive electronics using smaller
geometry processes, not the interface).


Date: 8/3/95 5:06 AM
To: Jim McGrath
From: Lee Cleveland
Subject: FC-AL connector question

A person working on packaging has a question he would like a answer for:

The FC-AL spec says something to the affect that 3.3 volts is required in the
connector to a device. He has received a device spec and this device does not
reference the use of 3.3 volts at all.

The Question

Is FC-AL spec of the 3.3 volts a real requirement or an optional one being
device does not reference 3.3 but does reference 5 volts?



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