why all the shortages on ceramic caps?

Thread Starter

joewales44

Joined Oct 8, 2017
218
what's up with ceramic caps?
price has skyrocketed and higher values are on backorder.
what's causing this?
one of my suppliers said demand was through the roof. is that right?
thanks
 

ebp

Joined Feb 8, 2018
2,332
Shortages of components happen all the time. Sometimes there are very severe shortages that cause a lot of grief.

The other old people here will probably remember the great TTL famines when electronic games were making a big splash and made TTL scarce. I once waited a full year for 74LS132s. I've been quoted 54 week lead time for power MOSFETs. Other vendors at the time were quoting 52 weeks, but only because their computer systems had that as upper limit.

Without knowing the specifics of the circuit it is hard to say how other types of capacitors would work. Sometimes you can use a smaller ceramic cap in parallel with a different type (e.g. tantalum) to produce a satisfactory result. This used to be a very common approach because high-value ceramic capacitors were much more expensive. It was also common to parallel two ceramic capacitors of different values, but that was largely due to inductance issues with through-hole parts - the higher value cap would have higher parasitic inductance because of the larger physical size and as frequency rose it would look more like an inductor than a capacitor - the impedance vs. frequency curve is a "V". SMT caps made that less of an issue because it became possible to get high-value caps in the same physical size as low value caps, though there are some ultra-tiny SM parts around that could still make it worthwhile in special cases. In a power application with large fast transients, the current tends to share among parallel caps in inverse proportion to their ESR, with actual capacitance playing a lesser role. If the capacitance is needed "only" for very fast transient currents, ceramic may considerably outperform alternatives. If there is also a lower frequency component, a composite cap might be OK.

If you can tell us more about the circuit, preferably with a schematic, we may be able to make better judgement of alternatives.
 

Papabravo

Joined Feb 24, 2006
22,059
It could be a number of things. We were once quoted a 26 week lead time, which we agreed to. 26 weeks went by and Siemens said sorry, our current production is for our German customers only. We said OK fine and designed their products out -- FOREVER!!

Material shortages affect things like capacitors from time to time. Now that bitcoin mining is becoming less profitable you can expect all sorts of dislocations.
 
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