Originally Posted by indulis
What does CCM have to do with the output current? Did you mean current mode control?
If it's a multiple output, your average primary current is going to be a lot more than 5A.
With 12V in, how do you consider that "off-line"?
You never mentioned in the original post that you were going with a buck-boost.
Sorry I went through my first post and true I havent mentioned buck boost... so ya it is a buck boost. Its off-line by the fact that during the ON period of T the inductor is the only thing that is charging and the load is off, during the OFF period of T the inductor is discharging and the source is off hence offline in operation i.e. the load is not being driven by the source but purely by the inductor
Originally Posted by indulis
How much current? 4 volts might be hard, but converters that run from 4.5-9Vin with 12Vout are available from many DC-DC manufacturers.
If you have looked at SwitchingPowerSuppliesAtoZ Maniktala's book you will realize that the equation V(on)*t(on)=V(off)*t(off) where V(off) is your desired output voltage, with V(on) being the input 12v you can manipulate the duty cycle to get your desired V(off) which will be the inductor discharge cycle voltage to the load and knowing its operating in Continous Conduction Mode which means you set t(on) and t(off) where T=t(on)+t(off) hence the inductor current never drops to 0. Essentially I will get all my desired voltages by just manipulating the duty cycle using a microcontroller connected to a sensor. So getting the 4v will be a breeze. Mind you I am making it not buy it because it will fit my needs perfectly. The current should be limited to 5A