5kW, 220VDC output, 175-300VDC input DC-DC converter requirement-reg

Hi Santhibhushan Addagarla,
There are may ways to achieve this specification.
If you do not require isolation between input and output then the smallest and most efficient solution will be a non-inverting Buck-Boost topology. Since TI do not produce a controller for this voltage range you will need to use an external regulator to supply the device and an external high-side driver device to extend the voltage range of the controller.
Please look at the link below for information about non-inverting Buck-Boost topologies.
www.ti.com/.../slyt584.pdf
An isolated design will be larger and less efficient. If you want to go in this direction then a hard-switched Full-Bridge or Phase-Shifted Full-Bridge could both be made to work.
You have not mentioned the range of load currents that are expected, or any full-load efficiency/light-load efficiency targets.
Best Regards
Joe Leisten

Thanks for your reply Mr.Joe Leisten,
For non isolated design, can you suggest us any IC or design?

Hi Santhibhushan Addagarla,
I think that the IC given in the link of the previous post should be suitable for your needs. You will however need to use an external low voltage supply to power the device. You will also need to use an external driver that is rated for the required output voltage such as the UCC27712 device.
I do not have a complete design to give you, but if you have a stab at generating a schematic I can review it for you.
Best Regards
Joe Leisten