2
\$\begingroup\$

Components on PCBs are usually labelled using silkscreen markings and most of the markings seem to be quite intuitive:

  • C?? - capacitor
  • D?? - diode
  • FB?? - ferrite bead
  • J?? - jumper wire
  • L?? - inductor
  • LED?? - light emitting diode
  • Q?? - transistor
  • R?? - resistor
  • RJ?? - RJxx connectors
  • SW?? - switch
  • T?? - magnetics (ex. for RJ45 connectors)
  • TP?? - testpoint
  • U?? - packaged integrated circuit

What could be the component marked as 'Y??' be? Unfortunately the board where I have this marking does not have this place populated.

[Edit] Wikipedia has a page about reference designators.

\$\endgroup\$
7
  • 4
    \$\begingroup\$ en.wikipedia.org/wiki/Electronic_symbol#Reference_designations \$\endgroup\$
    – starblue
    Commented Jul 13, 2011 at 20:53
  • \$\begingroup\$ @starblue, I guess we have a winner \o/ \$\endgroup\$
    – plaes
    Commented Jul 13, 2011 at 20:57
  • \$\begingroup\$ What is it connected to ? \$\endgroup\$
    – endolith
    Commented Jul 13, 2011 at 21:21
  • 1
    \$\begingroup\$ J is also used for connectors. \$\endgroup\$
    – stevenvh
    Commented Jul 14, 2011 at 4:24
  • \$\begingroup\$ @stevenvh yes I thought it was J for Jack and P for plug. Updated: nice link from @starblue. \$\endgroup\$
    – kenny
    Commented Jul 14, 2011 at 5:04

2 Answers 2

Reset to default
7
\$\begingroup\$

Y?? or X?? could both be a crystal or oscillator. Unfortunately there is no standard for this type of thing. If you posted a picture of the footprint we could take a better guess.

Also: Q=Transistor. RN=Resistor Network.

\$\endgroup\$
5
  • \$\begingroup\$ Footprint is 2 + 2 pins (square), so it cannot be crystal. Thanks for improving my list :) \$\endgroup\$
    – plaes
    Commented Jul 13, 2011 at 20:50
  • 1
    \$\begingroup\$ @plaes, not necessarily. Some crystals packages have 4 leads, even though crystals are only two-terminal devices. Square would be a bit unusual though. Still, I agree with David in that it's most likely a crystal. To really know, you'd have to check the BOM (Bill of Materials). \$\endgroup\$
    – Olin Lathrop
    Commented Jul 13, 2011 at 20:53
  • \$\begingroup\$ @Olin, getting access to BOM is a bit hard, because the PCB is from TP-Link router ;) \$\endgroup\$
    – plaes
    Commented Jul 13, 2011 at 20:56
  • 1
    \$\begingroup\$ It could be a crystal oscillator module such as one of these Euroquartz modules. \$\endgroup\$
    – MikeJ-UK
    Commented Jul 13, 2011 at 22:30
  • 2
    \$\begingroup\$ A great many SMD crystals are 4-pin devices! Digikey reports about 3000 in stock, and they're standard on everything we build at work. The oblong tin can with two through-hole connections is not the only type of crystal. \$\endgroup\$
    – Kevin Vermeer
    Commented Jul 14, 2011 at 0:14
1
\$\begingroup\$

I have seen Y used to label crystals and oscillators. This is how OrCAD labeled their library parts.

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.