It would be nice to know what exactly this thing is suposed to be powering.

Too often here we get people wanting to make things to ridiculously tight tolerances for applications that have zero justification for them.

Like '12 volt powered' devices from automotive applications where the person wants to make a home utility powered 12 volt volt power supply, that has +- .01 volt surge/sag tolerances with sub micro microvolt ripple just to run a device designed to work in an automotive electrical environment where anything from 8 - 18 volts with less than 4 volts peak to peak ripple is more than sufficient, type projects.

 

Linear Technology makes a number of inductorless charge pumps that are regulated. Some use analog regulation (the least noise) and some regulate "digitally".

They are not cheap -- $2 or more in low quantity -- but you don't need an expensive inductor.

The Linear Tech selection guide is here:
http://www.linear.com/docs/39287

Look in the Regulated Step-Up Charge Pumps section.

Here is one example:
http://www.linear.com/product/LTC1682

 

It would be nice to know what exactly this thing is suposed to be powering.

Too often here we get people wanting to make things to ridiculously tight tolerances for applications that have zero justification for them.

Like '12 volt powered' devices from automotive applications where the person wants to make a home utility powered 12 volt volt power supply, that has +- .01 volt surge/sag tolerances with sub micro microvolt ripple just to run a device designed to work in an automotive electrical environment where anything from 8 - 18 volts with less than 4 volts peak to peak ripple is more than sufficient, type projects.

The IC that I want to use only admits power from 3V to 12V to work. Because of a voltage drop from a diode I cant guarantee 3V and even without the diode, powering an IC that requires at least 3V with 3V battery supply wouldnt be recommended. That is why I would like to boost the voltage to constant 3V or a bit more 3.3V is common too

 

Just get a boost to 5V. I think those are very common. If you want build one, check out Minty Boost.

 

Because of a voltage drop from a diode I cant guarantee 3V and even without the diode, powering an IC that requires at least 3V with 3V battery supply wouldnt be recommended.

You can use a Schottky diode such as a 1N5817 to lose less voltage or, better yet, use a low threshold voltage MOS-FET to replace the diode (I have used the FDN338 -- an FDN338 will work almost as well).

 

You can use a Schottky diode such as a 1N5817 to lose less voltage or, better yet, use a low threshold voltage MOS-FET to replace the diode (I have used the FDN338 -- an FDN338 will work almost as well).

I know about the Schottky diode eventhough the voltage drop is still 3V. I have never used the low treshold voltage MOS-FET instead of a diode, I will read about it.

Thank you

 

I have never used the low treshold voltage MOS-FET instead of a diode, I will read about it.

You can start your search here:
http://www.electro-tech-online.com/...ion-of-input-power-with-low-voltage-drop.664/

Good stuff from another menber of this forum.