# How to identify this particular SMD component?

It is used on a small board RFID antenna circuit based on the TMS3705:

At the first check it seems to be a 0 ohm resistor, but the dimension 4x4mm its strange.

Any ideas?

L.

It is a "zero ohm link".

You can find them listed in the resistors section of a vendor's parts catalog.

It is typically used to turn on or off configuration options on the circuit board. The "0" marking is intended to make this stand out among a group of actual resistors.

They come in many sizes and even through hole versions. It is possible that this one is large in order to make hand-soldering easier.

• The through-hole ones typically have a single black band, which helps them to stand out among a group of normal through hole resistors. – Wossname Sep 2 '16 at 9:29

It is a 0 ohm resistor. They probably planned to have an inductor there, but replaced it with the 0 ohm resistor during testing/production preparation. It might be replaced to reduce cost. Or they might have it as a way of correcting the impedance of the antenna if needed. You can of course measure it using a multi meter.

• There's many more reasons to use 0R than just replacing inductivities; in fact, I've never seen that happen. – Marcus Müller Sep 2 '16 at 18:49

As others have said, it's a 0$\Omega$ resistor.

The reason why the unusual package is used is because they wish to minimize the inductance since it's in an RF circuit.

Here is a datasheet for resistors (including 0$\Omega$) in wide (side terminated) packages.

• As a side note, even though their 0 ohm value may imply 0W dissipation, these jumpers do have a max current rating (see table "Temperature coefficient and resistance range" on page 2 of the linked datasheet). Hence another rationale for big size in some designs (might not be the case here). – ghybs Sep 2 '16 at 17:52