6 ms·
Extreme 220GHz+Broadband Silicon Capacitor X2SC 0201M 22nF BV11
- rayiner 2mo agoI love the block diagram lol.
- thomasjb 2mo agohttps://www.digikey.ie/en/products/detail/murata-electronics/939120428422-T5S/29534815 https://www.digikey.ie/en/products/detail/murata-electronics... A mere 2.40 euros each!
- matherial 2mo agoAll silicon capacitors are relatively expensive, they're specialty parts that generally go into expensive things (mmWave airport scanners, optical backhaul, etc).
- kazinator 2mo agoThe temperature stability looks fantastic, but it has a voltage coefficient for capacitance which is worse than film caps. From datasheet: > Voltage <-0.1%/Volt That is significant: over just a 10V swing, it could be as high as 1%. For a plain old polyester film cap, this is something like ±0.0001%/Volt, IIRC. If you have an audio signal swinging over a -12 to +12 V range being coupled through a thing like this, there will be measurable distortion arising from ~ 0.1%/V variations in capacitance. Not that you would want to necessarily do that in the first place, since this thing has an 11V breakdown voltage, nothing to write Mom home about. There is no one-cap-fits-all; right cap type for the right job.
- queenkjuul 2mo agoI'm no expert but the doc says 73KHz-220GHz, this isn't intended for low frequency audio circuits
- mrheosuper 2mo agoConsider the device that they gonna be placed in, it's basically nothing.
- lisper 2mo agoWhy is this a component? Couldn't you just make one of these out of PCB traces?
- matherial 2mo agoNo, not if you want 22 nF. That's a pretty substantial capacitance. It would need to be quite big on a PCB. That would mean significant inductance, and thus, bad performance at high frequencies.
- bri3d 2mo agoCertainly not at these frequencies and corresponding high capacitance values; getting 22nF out of a PCB even with ECM would require quite a large surface area and at 220GHz you can't have that since your wavelength is so short; you'd just be making a giant resonator instead.
- Eduard 2mo agoECM = Embedded Capacitance Material. It is a special PCB laminate designed to create capacitance inside the PCB stack-up, typically between closely spaced power and ground planes.
- IndrekR 2mo agoLength of this capacitor is close to half-wavelength of 220 GHz (in vacuum). Using siblings of this broadband capacitor (40 GHz, same package) in some designs. In assembly, those require decent process control. This 0201M package is closer to 01005 passives in pad size. Typically no solder paste is used, just flux. Solder mask alignment has to be very tight (thin web used as a dam only). Cost per cap is reasonable where it is actually needed, other parts of the system are often orders of magnitude more expensive at those frequencies where performance matters. Where it gets the very high performance, is pillars/channels etched into silicon quite similar to how DRAM capacitors are made, just a “little bit bigger”. This allows for very low inductance and thus very high resonant frequency.
- SV_BubbleTime 2mo ago
- threatripper 2mo agoFigure 1 made me laugh out loud.
- aaronmdjones 2mo agoSame here. That's made my week.
- tedd4u 2mo ago1 •--||--• 2 Figure 1 block diagram
- stn8188 2mo agoIt may seem overly simplistic, but 2-port models for capacitors can be configured in series (as shown here) or in shunt (much more common for power distribution network applications). So, as basic as you might think this diagram is, it is entirely expected to be there so that we instantly know if the S-parameters are in series or shunt configuration - it would be more unusual if it were missing.
- Neywiny 2mo agoI think you're thinking of the other figure. Figure 1 has no connections at all
- burnt-resistor 2mo agoHey, at least we know it's not polarized. Knowing's half the battle.
- dlcarrier 2mo agoSomeone's actually using nF, instead of 0.022uF or 22,000pF.
- PowerElectronix 2mo agoI never understood why nF is less frequently used than uF or pF. To me, the logical thing is to express the capacity in units that are between 1 and 1000, like it's done with resistors and inductors.
- summa_tech 2mo agoI, too, had wondered; this seems particularly common in the US. My best theory is that in rough handwriting, n and u/μ can look pretty similar, and everyone sort of agreed to only use u to reduce ambiguity.
- nomel 2mo agoI heard this, and have witnessed it. One of my first jobs included board rework. There were several times when I had to go ask if they wrote a uF or an nF. The response was always "obviously a uF", because nobody uses nF!
- kazinator 2mo agoNobody uses nF in, say, digital, where the only caps are power supply filter caps and bypass/decoupling caps next to ICs. It's not customary to call a 0.1μF bypass cap 100 nF. If someone wrote in 100 nF for a decoupling cap, I would tend suspect they are trying to discourage a substitution like 82nF or 150nF and want to find out why. Whereas if it is 0.1μF, I know we can stick in a 0.2μF, if that's what we have on hand, and everything will be fine.
- kazinator 2mo agoAnother way to reduce ambiguity is to omit the suffix (unless it's p for picofarads) and let it be deduced from the numbers and symbols. 47 -> 47nF (if next to plain double bar symbol with no polarity markings) 47 -> 47μF (if next to polarized cap symbol) 0.47 -> 0.47μF 47p -> 47pF 10np -> np -> nonpolar -> electrolytic -> 10μF
- oakwhiz 2mo agoat what point do you start baking barium titanate into the PCB itself?
- IndrekR 2mo agoHas been done for decades. Buried capacitance materials like FaradFlex MC12TM exist and are really good, but are not too often used.
- burnt-resistor 2mo agoNonstock at Digikey US for $3.56 ea MOQ 1k, est. ship date middle of Feb 2027.