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I have a question about the hookup for my 12VDC to 5VDC step down module - the K7805JT-500R3.

It states in the datasheet that ceramic capacitors are what can be used but it also states that tantalum capacitors can also be used. It never says anything about being able to use aluminum electrolytic capacitors.

Are there any issues with me using aluminum electrolytic capacitors instead of the ceramic or tantalum capacitors?

enter image description here

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  • \$\begingroup\$ Internal resistance is different. LDO stabilization may b sensitive to it. You may try, because of the load it may works but may not. Results are not predictable. \$\endgroup\$
    – user263983
    Nov 25, 2023 at 10:04
  • \$\begingroup\$ You probably want to select a different regulator that is designed for electrolytic caps. \$\endgroup\$ Nov 25, 2023 at 12:53

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"Can" yes, there are situations where that can be done.

When, is the real question.

That question in turn, is answered jointly by these:
Ceramic (MLCC) versus Tantalum capacitors
Why do some switching regulator require tantalum or electrolytic capacitors instead of ceramic?

When replacing ceramic with electrolytic for power supply purposes, the value should probably be larger, so as to keep the ESR low. By how much, depends on the ripple current drawn, acceptable ripple voltage, and maximum capacitance limits of the supplies/converters used.

The datasheet gives a maximum 680µF load, and your 12V source may have a maximum figure as well.

The datasheet does not indicate whether ESR is required for stability or EMI, nor how applications might be concerned about ESR. It's probably safe to assume they're concerned about ripple, but beyond that, I don't know.

The values probably should not be less than specified.

Any value within these ranges should suffice. Do mind any other limitations not defined here (e.g. required PDN impedance range for downstream circuitry, etc.).

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  • \$\begingroup\$ Thank you for the knowledge Tim! \$\endgroup\$
    – StealthRT
    Nov 26, 2023 at 23:31

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