17
\$\begingroup\$

This question already has an answer here:

The loop ones. I've never seen them before.

none

\$\endgroup\$

marked as duplicate by Dmitry Grigoryev, PeterJ, Null, ThreePhaseEel, DoxyLover Jul 30 '17 at 18:13

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

  • 1
    \$\begingroup\$ Apart from the fine answers already here, I'd like to add that test points like these are rarely populated in actual production PCBs. They're usually only found in evaluation kit boards and prototypes. On production boards, the positions are often either left unpopulated, replaced with test pads (for automated bed-of-nails testing) or removed from the design altogether. \$\endgroup\$ – Mels Jul 28 '17 at 9:25
  • 3
    \$\begingroup\$ Depends on what industry your in, in mine we do a lot of testing on our boards, most of the older designs have these on our production boards \$\endgroup\$ – laptop2d Jul 28 '17 at 15:34
27
\$\begingroup\$

They are test points, as shown here.

enter image description here

They are suitable for mini-grabber connections to lab equipment or probing

\$\endgroup\$
28
\$\begingroup\$

TP is the designator for Test Point.

The plastic part just moves the loop part off the board, but you can see some without the plastic part. Nothing more than a small looped section of conductive wire. They can function as jumpers at the same time.

They are used for test clips to grab onto.

enter image description here

Some other options are 2 dimensional holes:

enter image description here

\$\endgroup\$
  • \$\begingroup\$ Do you by chance remember how these particular components are named? \$\endgroup\$ – Mast Jul 28 '17 at 7:01
  • \$\begingroup\$ Test point loops brings up results. \$\endgroup\$ – Passerby Jul 28 '17 at 12:25
  • \$\begingroup\$ Yes, but the ones posted by OP have a specific name I don't recall. \$\endgroup\$ – Mast Jul 28 '17 at 16:35
  • 2
    \$\begingroup\$ @mast digikey.com/catalog/en/partgroup/color-coded-test-points/19725 shrug \$\endgroup\$ – Passerby Jul 28 '17 at 16:49
13
\$\begingroup\$

As others say, these are test points. The coloured plastic rings can be used to indicate the type of signal on that test point. On the board in your picture, it appears that black testpoints are Ground. Red is for power - I see one labelled "+3.3V".

\$\endgroup\$
11
\$\begingroup\$

Test points for scope-probe hooks to grab securely.

\$\endgroup\$

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