# Question about current output of a DC-DC stepdown converter

If we have a solar panel of 5V and we want to keep voltage on the output to 3V, what current we are getting on the output? The same as in the input? Or a different one?

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The output power of the DC-DC converter is equal to the input power multiplied by converter efficiency. I assumed your DC-DC converter has an efficiency off 80%.

$P_{out} = P_{in} \cdot 80\%$

$3I_{out} = 5I_{in} \cdot 0.8$

$I_{out} = 1.33I_{in}$

But not always. You get the maximum current that is supported by the converter. If that limit is reached, then this equation is not true anymore.

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