MLCCs - Multilayer Ceramic Capacitors, anyone using these in-place of electrolytic's in our radio's?

[Klondike Mike]

Many advantages. Me not being a RF or Audio Engineer, I ponder how these new devices would operate in our vintage CB/HAM radio's. A few links of interest below;

https://product.tdk.com/en/techlibrary/solutionguide/mlcc_replace-guide.html

 

[nomadradio]

Some of them exhibit higher dielectric loss than the plastic-film type caps that are popular between 1 nf and a microfarad or so. Can make them less desirable in an audio circuit, especially if the signal level is more than a fraction of a Volt. The capacitance tends to change in step with the applied voltage. The larger the signal, the more this could introduce distortion.

Could.

Should be perfectly okay for filtering and decoupling, but the largest size they show is 100 uf.

A definite winner on lifetime.

73

 

[Klondike Mike]

As noted in the TDK document;

" ... it is important to note their shortcoming which is the large rate of change in capacitance due to temperature and DC bias"

Not a good feature to have in a mobile environment. I thought these MLCC's would have potential in our application. The good news (??) is that replacing electrolytics will continue to be a thing for a long time. I am probably one of the few out there that jumps for joy when the topic of replacing capacitors comes up. (Hi Hi).

 

[Handy Andy]

Ah yes, everyone doesn't think about needing a glass of water until the Well runs dry...

MLCC types - well I don't have really any good news about them - they are simple high-capacity farad caps "stacked" or interleaved, a lot like a battery and it's plates - they tried to reduce inductance - but generated another condition of drift as well as breakdown values were not all that great, not the best for RF use.

Midland and Maxon (Remember those?) used these in various 90's radios - some still work.

However due to their MLCC Package footprint - a difficult proposition to repair easily.

They've gained some respect thru the years but never made it past PC and PLCC eras'. Still power supply and rail noise applications but RF wise for our radios, not widely accepted

From the link...

*The weakness of the high-dielectric MLCC is the reduction in capacitance due to temperature or the application of a DC voltage (temperature characteristic, DC bias characteristic). In addition, the extremely low ESR feature can cause anomalous oscillations and anti-resonance to occur, so caution is needed when replacing capacitors.

Automotive Application PDF attached