G
Gary A. Crowell Sr.
Guest
In defense of the drafting drones, even simple op amps often aren't just
+in,-in,out triangles anymore. Add the trim/null, offset, filter, power and
whatever other pins are often there and it gets crowded to compress all of those
pins and labels into a reasonably sized triangle.
After some expensive layout errors in our system, we decided that all power pins
will always be shown explicitly on the schematic, not assumed or shown in a
table or left to a sub-part off in a corner somewhere. (The current test system
I work on has 13 separate voltage rails, and multiple ground areas.)
Now, having said that, we still use triangles when appropriate, but usually
boxes for the more complex parts, but then often place the triangle symbol
inside the box to satisfy the 'at a glance' folks. We use other logic symbols
'in the box' too, when its possible and appripriate to clarify a function that
is not obvious from the pin labels.
And, if there's any doubt, at least when viewing a schematic/layout on-screen
and on our network, a right-click brings up the datasheet on almost any part.
Gary Crowell
CAD system adminstrator/component librarian
Micron Technology
On Tue, 30 Sep 2003 22:52:22 +0100, Gareth
<gareth.harris@nobody.nowhere.invalid> wrote:
(__ (__ (__ (__ (__ (__
(__ (__ (__ (__ (__
(__ (__ (__ (________ V1.64
(__ (__ (__ (__
(_____ (____ (__ (__ Freeware CP/CG Calculator
(____ (______ (__ (c)1996 Gary A. Crowell Sr.
vcp@cableone.net
http://myweb.cableone.net/cjcrowell
+in,-in,out triangles anymore. Add the trim/null, offset, filter, power and
whatever other pins are often there and it gets crowded to compress all of those
pins and labels into a reasonably sized triangle.
After some expensive layout errors in our system, we decided that all power pins
will always be shown explicitly on the schematic, not assumed or shown in a
table or left to a sub-part off in a corner somewhere. (The current test system
I work on has 13 separate voltage rails, and multiple ground areas.)
Now, having said that, we still use triangles when appropriate, but usually
boxes for the more complex parts, but then often place the triangle symbol
inside the box to satisfy the 'at a glance' folks. We use other logic symbols
'in the box' too, when its possible and appripriate to clarify a function that
is not obvious from the pin labels.
And, if there's any doubt, at least when viewing a schematic/layout on-screen
and on our network, a right-click brings up the datasheet on almost any part.
Gary Crowell
CAD system adminstrator/component librarian
Micron Technology
On Tue, 30 Sep 2003 22:52:22 +0100, Gareth
<gareth.harris@nobody.nowhere.invalid> wrote:
(__ (__ (_____ (______ TMOur Drawing Office draws most components as rectangles which, in my
opinion, makes the schematic very hard to understand. Today I asked if
I could have amplifier symbols for my amplifiers and was told that
"nobody has triangles these days". Is this true or are our drawing
office just lazy?
I expect that what has happened is that they have become used to drawing
schematics consisting mainly of things like FPGAs, microcontrollers, etc
and don't see many analogue or discrete components.
What are peoples opinions on rectangles vs schematic symbols?
Thanks for any input,
Gareth.
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(__ (__ (__ (__ (__ (__
(__ (__ (__ (__ (__
(__ (__ (__ (________ V1.64
(__ (__ (__ (__
(_____ (____ (__ (__ Freeware CP/CG Calculator
(____ (______ (__ (c)1996 Gary A. Crowell Sr.
vcp@cableone.net
http://myweb.cableone.net/cjcrowell