[sdiy] [OT] LM13700 spotted in commercial product of big Manufacturer

[jslee]

On Thu, 19 May 2022, at 19:11, Gordonjcp wrote:
> On Thu, May 19, 2022 at 06:55:11PM +1000, jslee via Synth-diy wrote:
>> I was recently looking at Kicad again, wondering if it might finally be
>> feasible to implement an equivalent of my front-panel generation
>> software, and was astonished to find that it simply doesn't have an
>> equivalent of Eagle's DRU or CAM files. None. At all.
>> 
>
> What do those files do?

DRU: contains design rules. PCB fabs like Seeed, OSHPark, etc often provide this for Eagle users, but they're also easy to create from a fab's documentation. You load it and run DRC and it tells you if you've violated that particular fab's rules.

CAM: contains (a) a list of output files for a CAM process, and (b) mappings of design layers those output files, possibly with some settings like "create a negative image". Fabs often provide this for Eagle users, and of course they can be created easily enough. I tend to end up customizing CAM files to add layers into the silkscreen outputs, but other than that I use it as-is.

You might have multiple versions of these even for a single fab if you design boards with varying layer stackups.

In both cases, the files tend to encode details peculiar to a fab's process, and if you get them wrong (in any PCB software) you're potentially going to have a bad time. Hence my comments about human error. I would much rather load two files than manually configure Eagle (or Kicad, or ...) every time.

They are no substitute for reading and understanding a fab's spec, of course. But they help a lot.

John