30 Aug
2014
30 Aug
'14
8:35 p.m.
On a 4116, pin 1 is -5V, while the 4164 is N/C. Every guide online says
to snip off pin 1 if migrating to 4164s in a 4116 footprint, but I don't
understand why. If pin 1 on a 4164 is truly N/C, then why does it
matter if the pin is inserted?
Jim
--
Jim Brain
brain at jbrain.com
www.jbrain.com
30 Aug
30 Aug
8:42 p.m.
Quoting Jim Brain <brain at jbrain.com>:
On a 4116, pin 1 is -5V, while the 4164 is N/C. Every
guide online says
to snip off pin 1 if migrating to 4164s in a 4116 footprint, but I don't
understand why. If pin 1 on a 4164 is truly N/C, then why does it
matter if the pin is inserted?
Jim
--
Jim Brain
brain at jbrain.com
www.jbrain.com
i no longer remember the brand, but there is one or two manufacturers of 4164's
where pin 1 was connected internally to ground.
9:04 p.m.
On 08/30/2014 08:42 PM, Geoff Reed wrote:
i no longer remember the brand, but there is one or
two manufacturers of 4164's
where pin 1 was connected internally to ground.
I think that's correct--I believe there were some cases of 5V DRAMs
where "NC" actually turned out to mean "substrate".
--Chuck
31 Aug
31 Aug
5:59 a.m.
On Aug 30, 2014, at 23:35, Jim Brain <brain at jbrain.com> wrote:
On a 4116, pin 1 is -5V, while the 4164 is N/C. Every guide online says to snip off pin
1 if migrating to 4164s in a 4116 footprint, but I don't understand why. If pin 1 on
a 4164 is truly N/C, then why does it matter if the pin is inserted?
Because NC does not always mean "not connected"; sometimes it's meant as
"no-connect". Such pins are occasionally connected to test points, ground, etc.
But with enough trial and error, you could probably determine if it's safe on a 4164,
which may vary per brand and lot.
- Dave
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