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Pin # convention on SC75 (if there is one...)?

J

Joerg

Jan 1, 1970
0
Folks, what's the most prevalent pinout convention on SC-75 packages?
The Rohm 2SK3019 is one of them that I'll use and it's:

3
=====
2 1

I've seen others that are:

3
=====
1 2

and Infineon had yet another.

Is it the usual SOT-23 hodgepodge where every mfg rolls the dice and
takes it as they happen to fall or is there some consensus? In Eagle I
can assign them freely but I have seen some grief with other CAD packages.
 
G

Genome

Jan 1, 1970
0
Joerg said:
Folks, what's the most prevalent pinout convention on SC-75 packages? The
Rohm 2SK3019 is one of them that I'll use and it's:

3
=====
2 1

I've seen others that are:

3
=====
1 2

and Infineon had yet another.

Is it the usual SOT-23 hodgepodge where every mfg rolls the dice and takes
it as they happen to fall or is there some consensus? In Eagle I can
assign them freely but I have seen some grief with other CAD packages.

TO-92A
TO-92B
TO-92C
TO-92D
TO-92E
TO-92F
........

Now....... tell me about all the variants each manufacturer came up with to
cover the way EBC should be done in that lot.....

DNA
 
J

Joerg

Jan 1, 1970
0
Genome said:
TO-92A
TO-92B
TO-92C
TO-92D
TO-92E
TO-92F
.......

Now....... tell me about all the variants each manufacturer came up with to
cover the way EBC should be done in that lot.....

Well, if they'd somehow provide a "flavor suffix" that would be nice.
But they don't :-(

Thing is, if you do schematic and layout within the same package such as
Eagle there is no problem. But the millisecond you hand it off to a
layouter who uses another system that's different.
 
G

Genome

Jan 1, 1970
0
Joerg said:
Well, if they'd somehow provide a "flavor suffix" that would be nice. But
they don't :-(

Thing is, if you do schematic and layout within the same package such as
Eagle there is no problem. But the millisecond you hand it off to a
layouter who uses another system that's different.

Regards, Joerg

I think what you meant to say is that if you do it in house then there is
not a problem. However the level of that fallacy is something to be reckoned
with.

If you hand it out of house then....... CRAP.

Oooops, I would assume that if the first question that is not asked by the
out of house person is 'what does your models look like for all these bits'
you might not proceed further with their services.

Anyway, it's quite obvious to us experienced people that the pin on its own
side will be the collector/drain and the other two, looking from the top
will be the base/gate and emitter/source.

SORTED

DNA
 
J

Jim Thompson

Jan 1, 1970
0
I think what you meant to say is that if you do it in house then there is
not a problem. However the level of that fallacy is something to be reckoned
with.

If you hand it out of house then....... CRAP.

Oooops, I would assume that if the first question that is not asked by the
out of house person is 'what does your models look like for all these bits'
you might not proceed further with their services.

Anyway, it's quite obvious to us experienced people that the pin on its own
side will be the collector/drain and the other two, looking from the top
will be the base/gate and emitter/source.

SORTED

DNA

Yep. Screw the 1-2-3, screen the board with C-B-E... then it's the
fault of the assembly house ;-)

...Jim Thompson
 
G

Genome

Jan 1, 1970
0
Genome said:
I think what you meant to say is that if you do it in house then there is
not a problem. However the level of that fallacy is something to be
reckoned with.

If you hand it out of house then....... CRAP.

Oooops, I would assume that if the first question that is not asked by the
out of house person is 'what does your models look like for all these
bits' you might not proceed further with their services.

Anyway, it's quite obvious to us experienced people that the pin on its
own side will be the collector/drain and the other two, looking from the
top will be the base/gate and emitter/source.

SORTED

DNA

Bugger.... looking from the top with Collector/Drain at the top, reading
from left to right base/gate then emitter/source.

PROPERLY SORTED(?)

DNA
 
E

Eeyore

Jan 1, 1970
0
Genome said:
TO-92A
TO-92B
TO-92C
TO-92D
TO-92E
TO-92F
.......

Now....... tell me about all the variants each manufacturer came up with to
cover the way EBC should be done in that lot.....

But only *3* of them seem to be really popular ! :~)

Graham
 
J

Joerg

Jan 1, 1970
0
John said:
Always do it this way,




and ignore the mfr's convention. That's what we do with SOT-23's

Yep, guess that's what I'll do. Then frame it and give it to my
layouter. Maybe we could start an "s.e.d. convention on pinouts"...
 
J

John Larkin

Jan 1, 1970
0
Yep, guess that's what I'll do. Then frame it and give it to my
layouter. Maybe we could start an "s.e.d. convention on pinouts"...

It was, and still is, a gross error to make IC packages rotationally
symmetric. You couldn't plug a tube in wrong.

John
 
J

Joerg

Jan 1, 1970
0
John said:
It was, and still is, a gross error to make IC packages rotationally
symmetric. You couldn't plug a tube in wrong.

Yes, I never understood that either. Seems the semi industry is not very
competent when it comes to package and pinout standardizations. And it's
not rocket science. In medical we and most other companies had sent a SW
engineer to the DICOM meetings on a regular basis and now we all have
one common standard. When there is a noise problem I can run the pics
and video loops from pretty much any system right here in the lab, don't
even have to travel.
 
Q

qrk

Jan 1, 1970
0
Always do it this way,


and ignore the mfr's convention. That's what we do with SOT-23's

John

Use the IPC recommendations on pin numbering. Most companies adhere to
this. http://www.pcblibraries.com/ has a program with footprint
definitions of many SMT parts. It's free!
 
J

Joerg

Jan 1, 1970
0
qrk said:
Use the IPC recommendations on pin numbering. Most companies adhere to
this. http://www.pcblibraries.com/ has a program with footprint
definitions of many SMT parts. It's free!

Keyed in "SC-75" and "SC75". Did not match any... maybe they need a
better web designer?
 
J

John Larkin

Jan 1, 1970
0
Use the IPC recommendations on pin numbering. Most companies adhere to
this. http://www.pcblibraries.com/ has a program with footprint
definitions of many SMT parts. It's free!

What can this possibly mean?

"EU Council Directive 80/181/EEC Requires Products to use Metric
Beginning January 1, 2010, the European Union (EU) Council Directive
80/181/EEC (Metric Directive) will allow the use of only metric units,
and prohibit the use of any other measurements for most products sold
in the EU. This will make the sole use of metric units obligatory in
all aspects of life in the EU."

Does it mean we can't use ICs with pins on 0.1" centers? Does it mean
we can't make a pc board that's 5 inches square? Is it illegal to
specify the weight of a device on a datasheet in pounds? Must the
British stop using BTUs for refrigeration and miles for distances?


John
 
J

Joerg

Jan 1, 1970
0
John said:
What can this possibly mean?

"EU Council Directive 80/181/EEC Requires Products to use Metric
Beginning January 1, 2010, the European Union (EU) Council Directive
80/181/EEC (Metric Directive) will allow the use of only metric units,
and prohibit the use of any other measurements for most products sold
in the EU. This will make the sole use of metric units obligatory in
all aspects of life in the EU."

A typical example of the nonsense that a bloated bureaucracy comes up
with. Unfortunately that will lead to confusion with, among other
things, SMT. A 0402 cap is now also a 1005. What will definitely lead to
layout errors is that Eurocrats call the 0201 size "0603". Pretty stupid
IMHO.

Does it mean we can't use ICs with pins on 0.1" centers? Does it mean
we can't make a pc board that's 5 inches square? Is it illegal to
specify the weight of a device on a datasheet in pounds? Must the
British stop using BTUs for refrigeration and miles for distances?

I guess we've been there in US and the general population told body
politicus to ... <censored>.
 
L

Lostgallifreyan

Jan 1, 1970
0
What can this possibly mean?

"EU Council Directive 80/181/EEC Requires Products to use Metric
Beginning January 1, 2010, the European Union (EU) Council Directive
80/181/EEC (Metric Directive) will allow the use of only metric units,
and prohibit the use of any other measurements for most products sold
in the EU. This will make the sole use of metric units obligatory in
all aspects of life in the EU."

Does it mean we can't use ICs with pins on 0.1" centers? Does it mean
we can't make a pc board that's 5 inches square? Is it illegal to
specify the weight of a device on a datasheet in pounds? Must the
British stop using BTUs for refrigeration and miles for distances?

Just another bout of cucumber-straightening frenzy. Work to rule. Specify
your quarter inches in explicit 12 decimal place exactitude. That should
really get up their noses.
 
S

Spehro Pefhany

Jan 1, 1970
0
What can this possibly mean?

"EU Council Directive 80/181/EEC Requires Products to use Metric
Beginning January 1, 2010, the European Union (EU) Council Directive
80/181/EEC (Metric Directive) will allow the use of only metric units,
and prohibit the use of any other measurements for most products sold
in the EU. This will make the sole use of metric units obligatory in
all aspects of life in the EU."

Does it mean we can't use ICs with pins on 0.1" centers? Does it mean
we can't make a pc board that's 5 inches square? Is it illegal to
specify the weight of a device on a datasheet in pounds? Must the
British stop using BTUs for refrigeration and miles for distances?


John

The inch is defined in terms of metric units, so 2.54 mm pitch is an
exact metric dimension.



Best regards,
Spehro Pefhany
 
J

John Larkin

Jan 1, 1970
0
The inch is defined in terms of metric units, so 2.54 mm pitch is an
exact metric dimension.

So an inch is a metric unit!

Problem solved.

John
 
R

Rich Grise

Jan 1, 1970
0
1 inchmeter (im) = 25.4mm? Sounds good to me..

I like the 'im', but what do we use for the milemeter (??) = 1.609344 km? ;-)

Cheers!
Rich
 
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