EPROM Datasheet question

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bushnrvn's picture
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So I am getting into hardware dev and I am a total noob. I am trying to get some sockets for a prototype (so as not to keep soldering\desoldering) but I don't know what to make of the dimensions on the datasheet.

I am working with a couple AM27C256 EPROMs which come in a 14x2 28pin DIP configuration. I'm just trying to discern which measurements represent row spacing and pitch - as those seem to be the most relevant when selecting a socket.

Again - I've never looked at anything like this before - I could just measure it but I am away from my tools at the moment and I'd rather learn how to read this anyway.

Bottom of page 11 of the attached PDF.

Thanks!

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speedyG's picture
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Re: EPROM Datasheet question

Hello bushnvrn,

first of all it might be usefull to unterstand that the two measurement specified
are minimum and maximum measurements ( top minimum bottom maximum )
a ( ungiven medium value ) is the normal value....
spacing 0,1 inch is regular spacing
i dont know what you mean with pitch.... sorry...
distance between row with pins 1 to 14 and row with pins 15 to 28 is 0,65 inches.

At the other hand... if you just need the dimensions for the selection of the sockets....
that sockets are standard !
So the only 2 things to know if you want to order the sockets is:
pinamount and package-type.
pinamount is: 28 pins
and package type is:
Dual In Line package ( often shortened by the abreviation DIL or DIL-28 ).

At other chips you may also pay attention because there are 2 kinds of DIL packages ...

narrow and wide..... and in this case we are talking about wide ....
sincerely
speedyG

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bushnrvn's picture
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Re: EPROM Datasheet question

speedyG wrote:

i dont know what you mean with pitch.... sorry...
distance between row with pins 1 to 14 and row with pins 15 to 28 is 0,65 inches.

I take this to mean the distance between pins = pitch.

speedyG wrote:

At the other hand... if you just need the dimensions for the selection of the sockets....
that sockets are standard !
So the only 2 things to know if you want to order the sockets is:
pinamount and package-type.
pinamount is: 28 pins

I was going off this assumption but the Digikey search filters provided an overwhelming amount of information and options outside of this:

Digikey Sockets

speedyG wrote:

and package type is:
Dual In Line package ( often shortened by the abreviation DIL or DIL-28 ).

Just for my own understanding - is this the same as DIP?

Thanks!

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speedyG's picture
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Re: EPROM Datasheet question

DIP and DIL are normally same.
There are 2 measurements important:
distance from pin to pin within same row: 0,1 inch

and distance between 2 rows on opposite side of chip: 0,6 inch at "wide" cases.
Narrow or "normal" cases ( like at normal standard TTL chips i.e. 74LS10 )
at DIL or DIP have distance of 0,3 inches between the pin rows.

At the given link to Digikey for example:
the first 6 sockets have normal spacing between pinrows
while the 7th socket is "wide" type with double distance between pinrows.
( column 14 )

speedyG

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bushnrvn's picture
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Re: EPROM Datasheet question

Thanks. I ordered a tube of 10.

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