I have a requirement in my project wherein I need to multiply a DC voltage source four to five times. I have a DC source that can give 5 V at 1 Amps. I need to make it 20 to 25 V and the current can be less than 100 mA also. I have seen commercial ICs that can convert 5 V to 10 V, but this will not serve my purpose. It will be a great help to me if someone who has an experience with these kind of experiments suggests a nice solution. I am aiming at developing a board level circuit only, so I cant think of designing and taping out a circuit to fit for this purpose.