This is required circuit

 

 

OK, I missed that it is just a type of capacitor voltage doubler circuit. But varying the duty cycle has no significant effect on the output voltage. You can't use PWM as you would with a inductor type boost circuit. Its efficiency is also lower than an inductor based converter.

 

Ok then what modification should bring in this topology so it will act like conventional boost converter without inductor.There are numerous research articles on switched capacitor boost converter using different topologies on
IEEE and other journel papers which are not using inductors..

 

Don't know of any switched capacitor where you can control the output voltage unless you add a linear regulator to its output. That's why inductive type converters are common. Check those research and journal articles to see if any do allow control.

 

Don't know of any switched capacitor where you can control the output voltage unless you add a linear regulator to its output. That's why inductive type converters are common.

Yes, it is done. They are burst mode regulators. In other words, they skip pulses when the voltage gets too high. I have seen voltage converters that do a 1.5 to one step up for LED's using a charge pump. (I had the same opinion you did until I saw those.)

 

Yes, it is done. They are burst mode regulators. In other words, they skip pulses when the voltage gets too high. I have seen voltage converters that do a 1.5 to one step up for LED's using a charge pump. (I had the same opinion you did until I saw those.)

That would work although the output ripple voltage would vary in frequency and amplitude with the load current. For LEDs that's not a problem of course.