Efficiency of charge pump converter

[engr_joni_ee]

Hi, I read on Wikipedia "A charge pump is a kind of DC-to-DC converter that uses capacitors for energetic charge storage to raise or lower voltage. Charge-pump circuits are capable of high efficiencies, sometimes as high as 90–95%, while being electrically simple circuits."

Is this power efficiency ? I mean if the input power is for example 10 Watt, the output power can be 9.0 Watt to 9.5 Watt, right ?

I assume the input power is input voltage times the input current and the output power is output voltage times the output current.

 

[D.A.(Tony)Stewart]

Charge pumps are low in idle current but are not efficient at high current or all well load regulated.. They can be low noise but not cheap with all the caps and IC and rely on low RdsOn and low ESR.

https://www.digikey.ca/en/products/filter/special-purpose-regulators/750?s=N4IgTCBcDaIMYAsCGAnA5gUwAQAcCuAtjiALoC%2BQA

 

[engr_joni_ee]

The question is what is defined by the "efficiency". Is that power efficiency ?

--- Updated Mar 25, 2024 ---

Charge pumps are low in idle current but are not efficient at high current or all well load regulated.. They can be low noise but not cheap with all the caps and IC and rely on low RdsOn and low ESR.

https://www.digikey.ca/en/products/filter/special-purpose-regulators/750?s=N4IgTCBcDaIMYAsCGAnA5gUwAQAcCuAtjiALoC%2BQA

Kindly explain bit more. I am not getting it.

I understand the basic functionality of DC-DC converters, both buck converters and also boost converters. I know that in buck converter we get lower output voltages, but we can not get higher output power. The current can be higher then the input current but the output voltages has to be lower then the input voltages in such a way that the output power can not be more then input power. Usually it is between 80 % to 85 % which is called efficiency. Is that also true for boost converters and also for charge pump converters ?

 

[KlausST]

Hi,

my recommendation: Read a charge pump IC datasheet. It tells about efficiency.

The manufacturer of a chrage pump IC may provide additional informations (design notes, application notes, online calculators...)

Klaus