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When using a bulk capacitor would the type of capacitor matter? For example in an application where 100uF bulk capacitance is needed, would it matter if I use Tantalum, Ceramic, or electrolytic? Because in these situation I am tempted to go with a ceramic one because of much smaller size than the other two.

Also in another situation where 1000uF bulk is needed, which typically only electrolytic can achieve this value, would paralleling ten 100uF ceramics be okay since vertical space is limited compared to the board space?

EDIT: This question just popped into my mind and i am not currently creating a circuit. I understand that a more specific scenario is needed to answer the question. So to add to the question i have two scenario where i had and most likely going to use a bulk capacitor is in a buck/boost converter and a motor driver driver IC.

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    \$\begingroup\$ You've said nothing about your application. Is ESR important? Price? Space? Weight? Ruggedness? Availability? Ethically sourced components (Tantalum is, or was, considered questionable, because of where the mines are)? There's a reason there's hundreds of different capacitor types out there, when you burrow into all the sub-types. \$\endgroup\$
    – TimWescott
    Commented Aug 27, 2020 at 16:34
  • \$\begingroup\$ @TimWescott This is just a question that popped into my mind, I am not creating a circuit or anything but lets say the application is for a boost/buck converter or a motor driver bulk capacitor (these two are situations where i had needed to place a bulk) Price, space and weight are not significant factors. For ESR im not sure if its important to the two situations i mentioned? Which one would be best for ruggedness? \$\endgroup\$
    – Jake quin
    Commented Aug 27, 2020 at 16:47
  • \$\begingroup\$ It sounds like you're looking for the One True Answer -- there simply isn't one. If there were, there'd only be one type of capacitor sold. That's the point I was trying to make by citing how many different sorts of capacitors. It's your job as a circuit designer to know which components have what characteristics, and to choose wisely -- and sometimes the choice can be affected by the rest of the circuitry, and visa-versa. \$\endgroup\$
    – TimWescott
    Commented Aug 27, 2020 at 17:19

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It does matter, as each capacitor type has different properties that other type does not have. So it depends on what is important in the specific context.

For example, tantalums don't like current surges and can explode. Capacitance of a ceramic capacitor will depend on the voltage applied over them. Electrolytics have higher ESR and works poorly in cold and degrades fast if hot.

Also replacing a 1000uF electrolytic with ten 100uF ceramics will end up with absurdly low ESR compared to the original. That may be a bad thing in some applications, as current surges are higher and especially some applications may depend on the ESR to be within a specified range to be stable.

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  • \$\begingroup\$ I have edited the question to include a much more specific use case, but i do not know though if both of those are ESR sensitive applications. From what you have said it would seem the best capacitor type is the ceramic if not for its low values, would it be correct to say that to always use ceramic when possible and if the needed capacitance exceeds what ceramics offer go for electrolytic? \$\endgroup\$
    – Jake quin
    Commented Aug 27, 2020 at 16:57
  • \$\begingroup\$ Switch mode power supplies and motor drivers are extremely ESR sensitive applications as these involve high currents and high frequencies. Tantalums are not used much as ceramics have so high capacitance, and polymer electrolytics improve the ESR of standard electrolytics. There is also no single best capacitor, as it can be a combination of both electrolytics and ceramics to get the best of each capacitor, high bulk capacitance and low ESR and ESL. \$\endgroup\$
    – Justme
    Commented Aug 27, 2020 at 17:20

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