From: Andrew Jamieson <ajamiesn_at_mira.net>
Date: Mon, 10 Dec 2001 08:58:59 +1100

>The pin numbers on the DRAM don't seem to match those I see in the data
sheet.
>Am I missing something? You have drawn a 50-pin chip, but isn't the DRAM
chip
>a 44-pin TSOP-II?
>
>
>/Björn


Indeed it is a 44 pin TSOP-II, but it is numbered to 50 due to the missing 3
pins on each side. Ahhhh ... I just checked my datasheets - I used a
pin-replacement part from ICSI, as the ISSI web site was unaccessible when I
was looking, and they number the missing 3 pins on each side. The ISSI part
does not number these pins, and thus only gets to 44 pins.

So this is a question of preference (and ensuring your PCB designer is not
stoopid, if you were going to route the board). As the AJB actually
provides pads for the missing pins, I will keep the numbering as is (I would
guess it is how they have it on thier schematic so they can use a regular 50
pin SOJ package) .... If anyone has any really major objections, I may
change my mind.

Or I may not ;)
Received on 2001-12-09