Tonights Plan to Order 0.1µF Cap 1206 went Awry


#1

Link here: https://www.digikey.com/products/en?keywords=399-9305-1-ND

  • Current market demand for these product types have resulted in fluctuating and extending lead times. Lead times may differ.

Filtering “In stock”, and having the same specs, ends in zero to add to cart. Any ideas?


#2

Try the other usual suspects? There is RS, Mouser, element14 and whatever else you got locally?!
Or, if hobby, might try aliexpress or made-in-china or whatever else works.

And the obvious… going for a different form factor? 1210 maybe or put two or more smaller ones in parallel?

What material are you shooting for? X7R X5R NPR?


#3

The other way, 1206 is very large for a 100nF these days, 0603 is far more likely.


#4

Wow - there’s something strange going on! Mouser comes up with 41 matches for your basic spec (I expanded the voltage rating to include everything from 16VDC to 50 VDC). But where I expect to see tens of thousands of in-stock parts for the listed options, they show only a few hundred.

Is this a personal project, where you can get away with carefully hand-soldering an 0805 part onto a 1206 footprint? The 0805 versions seem to have slightly better availability.

Dale


#5

I am facing crazy lead times for many basic components.
1206 has been obsolete as general purpose for about 10 years, 0805 for about 5 years

1206 and 1210 are only for values like 10uF


#6

Welcome to the Great MLCC Shortage of 2018!

For the details, google for “mlcc shortage”. tldr; increased demand, but major manufacturers have pulled out due to low margins.


#7

A 1206 mill part is reasonably hand solderable. Also, a 1206 mill part is about the minimum size for a 22uf X7R part; yes there were some exceptions.

That Digikey has this now on their web sight:

Current market demand for these product types have resulted in fluctuating and extending lead times. Lead times may differ.

I’ve NEVER seen that before on Digi-Key’s pages.

From any particular country? Or, any particular part?

Lead times for other parts of my own project seem to also have affected reach; never expected a generic 0.1µF cap to be affected.


#8

I get 237 hits ? for 100nF~150nF 16-50V, any tolerance.
a few ~ 5c/4k are viable, but many choices, with highest stock 40,000 for 20%, 50V, 6.6c

16V is at the ‘we can’t bother’ end for 1206, as you can see by the price filtered output.
but if I really, really want 16v, then turns out I needed that 150nF ~ 14c !
Even some 120nF at 33c !! - but they are thick, so must be something special
Samsung claims “CAP, 120㎋, 16V, ± 5%, C0G, 1206”

Tip : Just box a little smarter than 98% of Purchasing Managers out there, and avoid either sides of the price sweet spot.


#9

I have never seen such a big COG dielectric, you think of <1000pF for them


#10

FYI, in mass produced equipments, I just had to replace all decoupling 100nF-X7R-0402 with 100nF-so-called-X5R-0201.
I did it under “friendly pressure” from the PCBA manufacturer.

Just received the first assembled samples this week. 0201 is smaaaall!

Most (non C0G/NP0) 0402 and larger MLCC are planned to be phased out in less than 2 year (at least for the ultra-high volume and ultra-low prices the industry wants).

There is a drawback at this small size, regarding DC behaviour (essential for decoupling operations).
The XR5 dielectrics used in 0201 MLCC (no X7R that I know of) have nothing in common with the good ol’ 0603 X7R-X5R, regarding C vs V.

X7R is indeed based around a temperature spec, but there is (was?) an “implied” V vs C behaviour that don’t seem to hold here.

Every 0201-X5R-100nF 16V to 25V I’ve checked loose over 80% of it’s capacity at 10-12V.
Looks more like a Y5V.
(Murata, TDK, EPCOS and many “much less known but high volume” Chinese/Taiwanese manufacturers).

I was surprised to see that these 0201 MLCC begin to be affected @3.3V (-50% @5V !)

Murata specs (other brands are similar) :

100nF-X7R-25V 0603
image

100nF-X7R-25V 0402
image

100nF-X5R-25V 0201
image


#11

Yes, surprised me too.
That even leads to a larger set of COG parts, that target ESD use as they have very low ESR

  • but there have to be other more creative uses too :slight_smile:

Take a look at this

Available capacitance tolerances of ±1%, ±2%, ±5%, ±10%, and ±20%
No piezoelectric noise
Extremely low ESR and ESL
Capacitance change is limited to ±30 ppm/°C from −55°C to +125°C.

That level of PPM is into the ‘good resistors’ area.


#12

Over at Do-It-Yourself Audio the hi-fi enthusiasts often suggest that COG is comparable to the best film capacitors in terms of distortion and freedom from parasitic effects such as ESR/ESL, dielectric absorption, etc.

Dale


#13

Those are some very disturbing graphs!

Dale


#14

My initial decision to use a 16V part was not based on the maximum working voltage rating of the part; instead was the capacitance stability over temperature.


#15

“COG” or “C0G”?

And, when did this become a thing?


#16

You get one point for my error. The correct designation is “C0G” (see-zero-gee).

Dale


#17
  • There is a worldwide shortage of MLCCs. It is expected to continue for another two years.

  • Larger physical sizes are generally more difficult to get than smaller sizes in consumer-grade. Automotive may be easier (but more expensive).

  • Loss of capacitance with DC bias is almost entirely related to size, not to voltage rating. The bigger (physically) the cap, the less its capacitance will depend on bias.

  • Smaller capacitors are less prone to micro-cracking from mechanical stresses.

  • For most decoupling, 10, 22, 47NF and others will probably work as well as 100NF.

  • Tantalum is an option, albeit usually more costly.

  • List item


#18

It took quite a lot of reading datasheets to get the point where my decision was made. The most significant concern was the ease of hand-soldering for the age of my eyeballs. Second, was that my design requires some larger capacitance that can not be had in smaller packages. Third was the ability to use two parts to halve the ESR.

It will be another week before I get back to the design process and attempt to make the changes such that parts can actually be added to cart.


#19

Tantalum typically is not a drop in replacement for ceramic. Not only is it polarized but also has different frequency behavior. (In most cases higher ESR)

simply putting two caps in parallel could result in strange frequency behaviors. (Resonance effects might occur. This depends on the exact frequency response of both caps. And of the PCB layout.)


#20

Or 805… I use that size for eveything I make since it’s relatively comfortable to prototype and I don’t often need much smaller.

Tantalum caps are preferable as PS filters due to thier higher ESR… ultra low ESR makes many regulators unstable.