"Michael A. Terrell" wrote:

Eeyore wrote:
gore wrote:

I work at an electronics contract manufacturimg facility. We do work for
several companies and I wonder why they use different labels on the
schematics and pcb's to refer to IC's. Some of them have a U1, an A1, and
X1, or an IC1. Why do they do this? Is there a standard used to label IC's
in a schematic? Just curious why this is.

X should be a crystal.
A would be an amplifier (I haven't ever seen that btw)
IC is self-explanatory and is widely used in Europe
U is some weird US practice. U for what ? Rumour has it that it meant
'unknown'.

Only outside the USA, by know nothing 'experts'.

The USA represents 5% of the world population.

Graham