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I would like to use an SMD assembly service in order to pick and place the components directly to my PCB. There is a DC-DC boost converter (DD06AJSA) on the board which includes an inductor:

enter image description here

I need to boost a 3,7V lithium battery up to 5V with a current draw of 500mA.

Is it possible to use a ceramic inductor instead of a wire wound inductor with the same value, so 6.8uH, like in the following picture?

enter image description here

Also: Unfortunately I have just 4.7uH as a choice, so would it still work as expected if I would choose a slightly lower one? In the datasheet for this IC FP6291 a value between 3.3uH and 4.7µH is recommended.

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  • \$\begingroup\$ "I need to run it with 5V and 500mA" - That is the output voltage and maximum load current, right? What is input voltage range does it need to work over? \$\endgroup\$
    – Bruce Abbott
    Commented Feb 12, 2021 at 5:23
  • \$\begingroup\$ Right, the input voltage is a 3,7V lithium battery. \$\endgroup\$
    – playmobox
    Commented Feb 12, 2021 at 5:49
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    \$\begingroup\$ Data sheet links for original inductor and proposed inductor are mandatory. \$\endgroup\$
    – Andy aka
    Commented Feb 12, 2021 at 6:58
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    \$\begingroup\$ "ceramic inductor instead of a wire wound inductor" For future reference, both inductors use ferrite, a type of ceramic. What you mean is a "chip type inductor instead of a drum core". Just an FYI. \$\endgroup\$
    – winny
    Commented Feb 12, 2021 at 9:04

3 Answers 3

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It could work, but look out for efficiency. Ceramic inductors tends to have quite a lot of DC resistance. If saturation current, average current and inductance are in the range needed for the circuit it can be worth a try.

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Most likely, you can't.

There is more to an inductor than just inductance. There is also current rating, winding resistance, core saturation current etc. In power conversion those can be even more important than the inductance itself, because it's where your inductor loses come from.

As a rule of thumb, if something seems to good to be true, it is. It's improbable that an element with fifth of the volume can have all parameters in same ranges.

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  • \$\begingroup\$ In other words it may work up to 10mA but not 500mA. \$\endgroup\$
    – user16324
    Commented Feb 12, 2021 at 14:34
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    \$\begingroup\$ Thank you for pointing me into the right direction: Indeed with each component there is also a specification of how much current is supported by that chip - right in the title - I didn't see this in the beginning \$\endgroup\$
    – playmobox
    Commented Feb 12, 2021 at 19:20
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I have used Ceramic Inductors in a boost converter(MCP16251T-I/CH0) to drive MCU(Atmega328PU). It worked (3.7 LiPO to 5V). Probably in high current applications, it won't work.

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