Re: How do you design these days?

"krw" <krw@xxxxxxxxxxxxxxxxx> wrote in message news:gj45k5tr1g3rqe72k3tbff33lnke7c5sdk@xxxxxxxxxx
On Mon, 4 Jan 2010 15:02:59 -0800, "Joel Koltner"
<zapwireDASHgroups@xxxxxxxxx> wrote:
That's the argument I get from the layout guy.

I know they exist (e.g., the guys at UltraCAD), but so far I've never worked anywhere where the layout guy was particularly "proactive" in the sense of suggesting interesting/potentially useful new ways to deal with parts management... they instead seem to always have a reason why, no, you can't do it the way you're suggesting (even though you've done so many times over somewhere else...). C'est la vie...

As you pointed out earlier, though, this can lead to corrections not
being propagated to all symbols.

Yes, with ORCAD that is a limitation.

[The power block]

I make it the last, to get it out of the way.

That's a bit more convenient, I just worry that I'll then forget it and that somehow a DRC run won't catch it either. (We don't have a "formal checklist" like John says he's working on to catch this sort of thing...)

I generally create the
"gates" from the front of the schematic to the back and the power
page(s) at the rear of the schematic.

That's how most of ours end up too. Things like multi-pin headers/connectors usually end up on the first page if they contain signals that go "all over." (I prefer to place one big symbol for, e.g., a header connector and then immediately terminate them in named off-page connectors. I've seen people break connectors into, e.g., 50 discrete pins and just placed them exactly where they were needed, but I've only done that once personally -- I like to see all the pins "together" to make it obvious whether I'm running, e.g., some high-power switched signals next to some millivolt level inputs.

The main campaign I go on WRT schematics is that, if your goal is to make it as clear as you can as to how the circuit operates, that effort is significantlly hampered by someone telling you there can only be one acceptable symbol for a given part. I even keep both a large and a small BJT symbol around and use the big ones for power (or otherwise "really important") devices and the small ones for generic switches other "lesser importance" functions.

---Joel

.

Relevant Pages

  • Re: How do you design these days?
    ... That's the argument I get from the layout guy. ... "gates" from the front of the schematic to the back and the power ... but I too prefer connectors at the ... see all the pins "together" to make it obvious whether I'm running, e.g., some ...
    (sci.electronics.design)
  • Re: Best Value for Schematic Capture & Layout Software ???
    ... Wintek made a naive little "drawing tool" for PCB layout ... to schematics ... digital or mixed signals designs? ...
    (comp.arch.embedded)
  • Re: Orcad is a total piece of dog crap!
    ... want to do it in that order, layout first then add it to the ... normally shown on schematics, like mounting holes or parts that are ... You don't really want the SCH ... With a common data base, ...
    (comp.arch.embedded)
  • Re: Schematic preferences
    ... Although you have to be careful that people don't mirror the symbol on you. ... I just put global connectors on the pins, ... global power pin might connect a dozen pins on a processor. ... The layout guy uses Allegro. ...
    (sci.electronics.design)
  • Re: Wanted: LM-709 (Spice model) National Op-Amp
    ... let me explain why I decide what package to use based on the ... > a client does not care about SPICE runs. ... > well as the layout software. ... Aren't LVS or "Layout versus Schematics" tools known in your work? ...
    (sci.electronics.cad)