Author Topic: The Dirty World of Resistors  (Read 6400 times)

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Offline ondrejiTopic starter

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The Dirty World of Resistors
« on: August 13, 2014, 06:57:28 am »
Hi,

I had a brief look at Digi-Key SMD resistor selection (around 120 000 SKUs) and here are some insights:

  • Number of manufacturers: 23
  • Top 3 manufacturers: Panasonic Electronic Components, Rohm Semiconductor, Vishay Dale
  • Values: 1015
  • Resistance range (excl. 0Ohm): 0.0002Ohm - 25GOhm
  • Top 10 values*: 10k, 0, 1k, 100k, 100, 4.7k, 10, 1M, 47k, 49..9
  • Top 10 packages*: 0603, 0402, 0805, 1206, 0201, 1210, 2512, 2010, 01005, MELF-0204
  • Top 10 tolerances*: 1%, 5%, 0.1%, 0.5%, 2%, 0.05%, 10%, 0.01%, 0.02%, 0.25%
  • Price (per quantity in AUD):
    • 0.02 -  34.30 @ 1
    • 0.088 - 5.756 @ 10
    • 2.435 - 22.570 @ 100
    • 0.02796 - 8.733 @ 1000
    • 0.00061 - 0.35630 @ 10000
(*) are based on stocked quantities

Resistor Quadrants

All 23 resistor manufactures can be placed into one of the four quadrants based on:
  • product line uniqueness
  • single quantity price
The four quadrants are:
  • Unique and expensive resistors: Only “Vishay foil resistors” who is famous manufacturer of precision resistors occupies this quadrant.
  • Usual resistor range with special features. Sfernice manufactures MIL spec, aerospace, and medical resistors. Anaren’s speciality is RF
  • Your everyday resistor needs - mass production at low cost. This 10k should be good for pull-up, right?
  • Unique products but the competition keep price down.
The manufacturer position might not be correct because the dataset contains Digi-Key stocked product only. For example Digi-Key can stock the majority of values / types / etc from one manufacturer and fill the gaps with cheaper parts from the other manufactures. It would be interesting to see change in manufacturer quadrant position if data from multiple distributors are analysed (Hey, Octopart can I use your data?).

The average Joe Resistor
looks like this:
  • Tolerance: 1%
  • Power: between 0.125W and 0.1W
  • Composition: Thick Film
  • No special features
  • Temperature Coefficient: ±100ppm/C
  • Package: 0805

Enjoy!

Edit: this forum doesn't like unicode characters :(
« Last Edit: August 14, 2014, 12:23:13 am by ondreji »
 

Offline T3sl4co1l

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Re: The Dirty World of Resistors
« Reply #1 on: August 13, 2014, 07:16:41 am »
Cool!

...I still have no idea what to buy :( :-DD

Tim
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Offline calmtron

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Re: The Dirty World of Resistors
« Reply #2 on: August 13, 2014, 08:13:16 am »
You gotta love statistics in this business :D
 

Offline alanambrose

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Re: The Dirty World of Resistors
« Reply #3 on: August 13, 2014, 04:08:48 pm »
I think this is pretty interesting, and thanks. I just did something similar for capacitor pricing and package size. Just as the assumption that a trace has zero impedance is good a lot of the time ... until it isn't - then, by analogy, assuming a universal resistor population exists i.e. that you can get all resistors in all values at all tolerances at cheap prices works most of the time ... until it falls down badly.

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Offline dannyf

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Re: The Dirty World of Resistors
« Reply #4 on: August 13, 2014, 04:12:06 pm »
Quote
Enjoy!

Thanks. It is an excellent analysis for the distributors, sourcing departments, management and even engineers - to encourage people to design to / stock those most common parts.
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Offline c4757p

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Re: The Dirty World of Resistors
« Reply #5 on: August 13, 2014, 04:13:02 pm »
Whats the point ? Why did I waste time reading that ?  Why did you waste time posting that ?

What's the point? Why did I waste time reading that?  Why did you waste time posting that?
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Offline Richard Crowley

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Re: The Dirty World of Resistors
« Reply #6 on: August 13, 2014, 04:33:12 pm »
Whats the point ? Why did I waste time reading that ?  Why did you waste time posting that ?

What's the point? Why did I waste time reading that?  Why did you waste time posting that?
It seems quite probable that brevor didn't get the point of THAT either.
Have we lost the concept of "lurking" for a while to get the hang of things before posting?

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Offline amyk

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Re: The Dirty World of Resistors
« Reply #7 on: August 13, 2014, 08:48:10 pm »
That minimum for the price is interesting: $27.96 for 1000, or $6.10 for 10000? :o
 

Offline mikeselectricstuff

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Re: The Dirty World of Resistors
« Reply #8 on: August 13, 2014, 10:14:52 pm »
Some stats missing....

Total number of resistors in stock.
Total resistance of all resistors in stock.
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Offline rob77

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Re: The Dirty World of Resistors
« Reply #9 on: August 13, 2014, 10:59:07 pm »
Some stats missing....

Total number of resistors in stock.
Total resistance of all resistors in stock.

those are the useless numbers very often required by the management - especially the "total resistance of all resistors in stock" and probably compared to the "total resistance of all resistors in the know universe" to calculate the market share  :-DD  :-DD
 

Offline ondrejiTopic starter

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Re: The Dirty World of Resistors
« Reply #10 on: August 14, 2014, 12:21:11 am »
Some stats missing....

Total number of resistors in stock.
Total resistance of all resistors in stock.

Total number of resistors in stock is 3 127 734 769! (and the other number is almost 1E(xa) Ohm)
 

Offline Smokey

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Re: The Dirty World of Resistors
« Reply #11 on: August 14, 2014, 01:46:38 am »
I love it.  Don't ever get between a nerd and his data! 
I've spent all day writing scripts to collect and analyze data like this before with the only end result being me sitting back and thinking to myself... that's cool.  now what's next :)
 

Offline digsys

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Re: The Dirty World of Resistors
« Reply #12 on: August 14, 2014, 02:06:27 am »
+1 :-)
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Offline chicken

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Re: The Dirty World of Resistors
« Reply #13 on: August 14, 2014, 02:10:26 am »
I think the price ranges are screwed up. A quick test found 0603 100R for 0.004 @100 and 0.002 @1000
 

Offline free_electron

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Re: The Dirty World of Resistors
« Reply #14 on: August 14, 2014, 02:53:16 am »
other statistics missing :
power rating
flashover voltage
thin or thick film


statistics like this are nonsense. pick the part needed for the job.
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Offline zapta

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Re: The Dirty World of Resistors
« Reply #15 on: August 14, 2014, 02:55:35 am »
Some stats missing....

Total number of resistors in stock.
Total resistance of all resistors in stock.

Total number of resistors in stock is 3 127 734 769! (and the other number is almost 1E(xa) Ohm)

What is the average cost of 1 ohm of resistance in stock?
 

Offline ondrejiTopic starter

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Re: The Dirty World of Resistors
« Reply #16 on: August 14, 2014, 03:04:08 am »
I think the price ranges are screwed up. A quick test found 0603 100R for 0.004 @100 and 0.002 @1000

Yes, you can say that, I agree. Those prices are based on "Minimum Quantity" column. I didn't scraped individual resistor pages and the price breaks.
 

Offline ondrejiTopic starter

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Re: The Dirty World of Resistors
« Reply #17 on: August 14, 2014, 03:12:52 am »
What is the average cost of 1 ohm of resistance in stock?

So if you want to buy just one: $1.474 (AUD)
Code: [Select]
   Min. 1st Qu.  Median    Mean 3rd Qu.    Max.
  0.020   0.120   0.430   1.474   0.925  19.930
 

Offline wagon

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Re: The Dirty World of Resistors
« Reply #18 on: August 14, 2014, 03:20:11 am »
That minimum for the price is interesting: $27.96 for 1000, or $6.10 for 10000? :o
I used that system to my advantage recently.  Some electrolytics I needed were 6.6 cents each upto 100 pieces and 6.4 cents each for 100-500pieces.  I bought 101 pieces. $6.60 for 100 and $6.46 for 101.
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Offline T3sl4co1l

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Re: The Dirty World of Resistors
« Reply #19 on: August 14, 2014, 05:33:28 am »
Generating a BOM from Altium, you can output the purchase quantity, which includes extra quantity to reach the next price break if it's cheaper.  Or you can write a rather tedious Excel expression to do this from the Supplier Pricing field.  Which also works (with some changes) if you're building the BOM by hand, copy-pasting the raw supplier data.

Occasionally, suppliers themselves will ask if you want to bump an item to the next price break, because it's easier (cheaper) for them, too.

Tim
Seven Transistor Labs, LLC
Electronic design, from concept to prototype.
Bringing a project to life?  Send me a message!
 


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