I am looking for design of a DC to DC converter where input DC is 12 or 24V direct from battery and output required is 300V, 450V 600V DC, any one at a time. And this output is required to be regulated at 4 to 5 slabs of voltage. E.g. considering 12 to 300V converter having 300V, 200V, 150V 100V, 50V as the regulated outputs. One of the standard way could be to use DC to AC inverter and then control back to DC after rectification. But here I need not use Inverter at 50Hz/60Hz, it can be any frequency. Does any of the PI device used in this application? If yes, How, even if it is used partially it is OK.