Lead is no problem for RoHS-exempt components. If they can use these superlattice caps to replace tantalum caps, I'm all for it. Those suckers take up so much space in small designs that you sometimes have to forego the recommended decoupling caps just to get the design to fit on the board.
Out of interest, why do tantalums get used so much over ceramics (or electrolytics even) for bulk decoupling? DC bias can be a pain I know, but I always thought of ceramics as cheaper / less fiery alternatives.
They were more compact than alternatives at the time, and had lower ESR. This made them especially desirable for supply decoupling in digital logic, whose random fast edges means a lot of broadband noise to shunt — you can't just design to a particular frequency range like you can with most analog circuitry.
Digital was also the new expensive hotness, and putting in a tant wasn't going to be a big fraction of BOM cost.
These days my understanding is that ceramics and non-tantalum electrolytics have gotten good enough to replace most tantalum uses, and between that, the expense, the slavery, the exploding, and the environmental damage, they're less common than they once were.
What’s an application that needs to be super small, but doesn’t risk getting lead into people’s bloodstream and the environment? I can’t think of many…
The problem is that most electronic components are RoHS today. So getting these into other devices will mean loss of RoHS certification, and that is something a lot of companies don't want right now due to the environmental movement. Many use that as a selling/marketing point.
I'm hoping for other superlattice materials to become available.
But RoHS permits lead if there's no reasonable alternative. One example is lead acid batteries which contain a lot of lead. A similar exemption could be made for these I guess if they're really that promising.
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Digital was also the new expensive hotness, and putting in a tant wasn't going to be a big fraction of BOM cost.
These days my understanding is that ceramics and non-tantalum electrolytics have gotten good enough to replace most tantalum uses, and between that, the expense, the slavery, the exploding, and the environmental damage, they're less common than they once were.
higher energy density
> (or electrolytics even)
no risk of drying up. Also, higher energy density, especially for small parts.
I'm hoping for other superlattice materials to become available.
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