Category Archives: PCB Mechanic

The PCB Mechanic – Datasheet Torture

Datasheet torture – what is this? Anyone who has tried to create library parts will know exactly what this is about. A classic example is this Micrel component, where the manufacturer is trying to convey the required footprint information to a PCB designer or engineer who need to create an accurate PCB footprint for their design.

Have a look at it, at first it seems simple but on closer inspection we see that they’re trying to convey some kind of L shaped land and then the hatched area seems to denote something. But we don’t know what.

Datasheet

This means that the engineer really isn’t being informed well. Then look even closer at the bottom, the wonderful disclaimer that basically says, follow these instructions but don’t blame us if it goes wrong.

I’m sorry, but this is crap! The part manufacturer is really taking no responsibility here and let’s be honest isn’t doing a good job of trying to make life easy for the engineer. Sure they’ll take your money if you buy the parts but we’re not going to help you design it in and don’t cry to us if it goes wrong.

That’s bad business and bad service.


 

There’s also a big problem when we arrive at the situation of large IC’s with 100 plus connections. The problem? The pin assignments. The order that the pin details comes in often seems pretty random. I hear the echos of “What sadist wrote this datasheet?!?” from one engineer who was trying to decipher the pin arrangements of a BGA. My only insight was that it might make sense at the die level – totally useless and meaningless for the PCB design level.

I’ve said before in Circuit Mechanix that component technology is driving PCB designers and fabricators to design boards that are increasingly advanced, the problem is that the manufacturers of these devices are NOT helping engineers to design in these parts properly. Fanout information including the right drill patterns is often not included in datasheets or is poor. Key information isn’t clear or is misrepresented and this is leaving engineers and designers bewildered.


 

My message is clear and I’m sure I’m not the only one who would echo this: Component manufacurer’s sort your act out and sort your datasheets out! Help us design these parts properly into products but giving us good information because with a few exceptions most of you are doing a terrible job at this!


PCB Mechanic
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