SMD resistor tolerances

[Super_Pseudo]

No tolerances are listed for SMD resistors, only the value, on pcbs.

If I had a 1R0 Ω (i.e. 1.0 Ω), would a 1.5 Ω in-circuit reading be bad (+50%)? Or do they not go bad?

Ty.

[eccerr0r]

Re: SMD resistor tolerances

make sure you zero out your meter first.

[Super_Pseudo]

Re: SMD resistor tolerances

Do you have an answer on smd resistor tolerances?

[jiroy]

Re: SMD resistor tolerances

First of all , resistors and eventually most of the components should be tested outside board when dealing with resistance .
That's said , SMD Resistors as an international standard (there will always be some exception and especially from amateur companies if I may say so) , are typically 5% tolerance when they are labeled in 3 digits , and 1% tolerance when labeled 4 digits .. Hope this help you .

[eccerr0r]

Re: SMD resistor tolerances

A resistor won't read higher than its written/banded value (within tolerance) in-circuit when the circuit is off and completely discharged. Again the most likely cause for reading low value resistors (say less than 5 ohms) higher but within about 70% of their stated resistance is due to measurement error. A Kelvin connect is much preferred to do these measurements but most DMMs do not have this functionality.

Usually SMD resistors like any resistor will go open circuit by a lot when they fail. Having it increase a mere 50% is very uncommon.

I haven't seen many SMD resistors that are more than 5% tolerance and quite a few of them are 1% or better, unlike typical gold-band ¼W and ⅛W through hole resistors...