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Author Topic: I get confused so easily - I cannot find this resistor size  (Read 720 times)

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Offline ThermallyFrigidTopic starter

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I get confused so easily - I cannot find this resistor size
« on: October 23, 2021, 03:20:26 am »
Hi again,

Sometimes it feels like life is out to get me.

Here is a photo of today's dilemma.  I have no doubt it will take you 2 seconds to tell me how easy this was to Google or otherwise find out, but I searched for a while on Mouser, Google, DigiKey etc and could not find an answer.

Basically as you can see in the photo, I have a 51R0 resistor that measures approximately 9.88mm.
However, according to the chart inset, there is no such thing ?   6.3mm is the largest SMD resistor.
Why is the resistor in the image nearly 10mm in length and yet according to SMD resistor charts they only go to 6.3m ???

A bit more explanation......without measuring the pads on the PCB, I get the approximate size in the chart....but I'm working in KiCAD and when I put the footprint down it is too small.
Maybe the problem lies in the KiCAD footprint sizes?
The spec sheets say this is a 1206 size SMD resistor.
When I pick that footprint in KiCAD, the footprint is too small.
It's like I have to custom make a footprint for this...even though 1206 is a very common resistor size.



These kinds of things delay me often and throw hurdles at me.  I would imagine no one else has these kinds of problems.
It's hard not to let it drive one crazy.  I'll bet this is one of those things that requires a special kind of dumb to not figure out.

Thanks for explaining and please pardon my frustration.
« Last Edit: October 23, 2021, 03:26:31 am by ThermallyFrigid »
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Offline sleemanj

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Re: I get confused so easily - I cannot find this resistor size
« Reply #1 on: October 23, 2021, 03:31:20 am »
Photo clearly shows you are not measuring the resistor correctly, you seem to be measuring from the ends of the pads, not the ends of the resistor.

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Offline ThermallyFrigidTopic starter

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Re: I get confused so easily - I cannot find this resistor size
« Reply #2 on: October 23, 2021, 03:55:37 am »
Quote from: sleemanj on October 23, 2021, 03:31:20 am
Photo clearly shows you are not measuring the resistor correctly, you seem to be measuring from the ends of the pads, not the ends of the resistor.

I know.
Maybe this is more of a KiCAD question than a SMD resistor question.

My apologies.
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Offline MarkF

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Re: I get confused so easily - I cannot find this resistor size
« Reply #3 on: October 23, 2021, 06:17:54 pm »
I use Diptrace.
And the latest version has three different sizes for SMD passive pads (least, nominal, maximum).
See this description:  https://www.ultralibrarian.com/2020/12/03/0603-package-footprints-and-sizes-of-smd-passives-ulc

It's the users choice to meet their design requirements.
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