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Charge pumps use capacitors and not inductors. https://en.wikipedia.org/wiki/Charge_pump

Boost converters require inductors. https://en.wikipedia.org/wiki/Boost_converter

Both charge pumps and boost converters seem to serve the same purpose. Would charge pumps be preferable given that it does not use inductors? What are the pros and cons of charge pumps versus boost converters as DC-DC converters?

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  • \$\begingroup\$ well, if you don't like inductors for some reason they are. \$\endgroup\$ – Jasen May 22 '16 at 5:15
  • \$\begingroup\$ inductors tend to be bulky. Are there occasions when boost converters are preferable? \$\endgroup\$ – user768421 May 22 '16 at 5:16
  • \$\begingroup\$ I have never used a charge pump IC. I have used boost controllers many times. I have seen charge pumps integrated into IC's when they did not need large amounts of current. For example, maybe they just need to generate a high voltage to turn a high-side NMOS gate on. If the amount of current needed is 100 mA or more, I think you will usually be better off with a boost regulator due to efficiency. \$\endgroup\$ – mkeith May 22 '16 at 6:37
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Boost converters can be efficient at a continuous range of voltage ratios. Charge pumps work best at fixed ratios. and for ratios other than (approximately) 2:1 or -1:1 they become increasingly complex.

I've got a 2W boost converter (5V to 12V) here that has an inductor about as big as a tic-tac, I've never seen a 2W charge pump.

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Charge pumps are inherently inefficient when used as voltage converters: charging (or discharging) a capacitor loses some energy. Always. Even with ideal components.

An ideal inductor-based voltage converter can be lossless. An inductor-based current converter has the same problem as a capacitor-based voltage converter.

We mostly work with fixed voltages, so an inductor-based converter is generally preferred.

There are some answers on this site that elaborate more on this, including discussions about the unavoidable loss when charging a capacitor from a fixed voltage.

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