Tolerance rating on a 0 Ohm resistor?

In summary, a 0 Ohm resistor is not actually a perfect conductor and therefore has a finite resistance. The tolerance rating of 5% is used to account for this resistance and can be found in the datasheet for the specific 0 Ohm jumper. While it may not make sense to use a percentage for such a small resistance, it is a practical way to indicate the tolerance. A 0 Ohm resistor is not the same as a fuse and is not designed to be used as one due to its construction and potential for corrosion and healing.
  • #1
TheAnalogKid83
174
0
Tolerance rating on a 0 Ohm resistor?

I'm just curious why the zero ohm "jumper" resistors I use have a tolerance rating of 5%. This doesn't really make sense to me because 5% of 0 Ohms is still 0 Ohms. I understand that even a close to ideal conductor is not going to be 0 Ohms, but why do they use a percentage of 0 to show the tolerance rather than say [tex]\pm[/tex] 0.1 Ohms??
 
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  • #2
also, i just realized you can't really have a +/- on a 0 ohm, but just a + (no negative resistance), just wanted to extinguish that before someone called me out on it :D
 
  • #3
Yeah, that's an old running joke in EE. Tolerance on a "zero ohm jumper" -- LOL.

But as a practical matter, they do make most 0-Ohm jumpers with resistor fab techniques (well, not the old simple wire jumpers), so there will be some finite resistance associated with the jumper, and maybe for some applications, knowing the resistance will be important. The datasheet should give a more practical resistance maximum for the particular 0-Ohm jumper. If it doesn't, just use 5% of the next higher resistor in the family, usually 1 Ohm.
 
  • #4
Alright thanks for explaining that, I was afraid it was going to be some complicated statistical explanation :D
 
  • #5
A zero ohm resistor is a fancy word for a fuse. I admit they look different.
 
  • #6
capnahab said:
A zero ohm resistor is a fancy word for a fuse. I admit they look different.

Not necessarily, in fact, 0-Ohm jumpers are never used as fuses, AFAIK. They are not built to act as fuses. The are used as option straps, usually, or as optional grounding paths for ESD cofigurability of a final PCB design based on final ESD testing.

A fuse does have a finite, low resistance, with some tolerance. I've used low-current fuses as "blow-able" option straps in products that get configured in production to be an expensive version (fuse unblown) or a cheaper version (fuse blown). I've also used cuttable wire jumpers as cheap configuration straps in products that had multiple personalities, where the option is set once, and must never change (so no DIP switches).

A 0-Ohm SMT resistor would be a poor choice for a fuse, because the current and voltage required to reliably blow it open would not be well constrained by the construction, and because the resulting open would be subject to corrosion and potential healing. Not good.
 
  • #7
Scusa, I should have said act as a fuse in event of short circuit.
 

1. What is a tolerance rating on a 0 Ohm resistor?

A tolerance rating on a 0 Ohm resistor is a measurement of the resistor's ability to maintain its specified resistance value. It indicates the maximum percentage by which the actual resistance may deviate from the stated value.

2. Why is a tolerance rating important for a 0 Ohm resistor?

A tolerance rating is important for a 0 Ohm resistor because it ensures that the resistor will function within a specified range and not significantly deviate from its stated resistance value. This is crucial for maintaining accuracy and reliability in electronic circuits.

3. How is a tolerance rating determined for a 0 Ohm resistor?

A tolerance rating for a 0 Ohm resistor is typically determined by manufacturing processes and quality control measures. It is often specified as a percentage, such as ±1% or ±5%, indicating the maximum range of deviation from the stated resistance value.

4. What factors can affect the tolerance rating of a 0 Ohm resistor?

The tolerance rating of a 0 Ohm resistor can be affected by various factors, such as the materials used in its construction, the precision of the manufacturing process, and environmental conditions such as temperature and humidity. These factors can impact the overall accuracy and stability of the resistor's resistance value.

5. How does the tolerance rating of a 0 Ohm resistor compare to other resistors?

The tolerance rating of a 0 Ohm resistor is typically lower than other resistors, as it is designed to have a very precise and consistent resistance value. Other resistors may have higher tolerance ratings, allowing for a greater range of deviation from the stated value.

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