All the cheap A.C. inverters have a high frequency switching boost transformer power supply that creates about 155 vdc output. This is followed by a MOSFET H-bridge that creates the modified sinewave output to A.C. socket.
If your are looking for 150 vdc from A.C. mains I am sure there is switching power supply out there somewhere.
You could easily build a buck to do that. However, it would be running at only 20% duty cycle so it wouldn't be real efficient.... still way more efficient than a linear.
Any links or suggestions? The only bucks I've "designed" are using national semiconductors web bench, and they don't seem to have a solution for what I need.
What is your load? A DC source, or does transient response matter?
You can totally made a DC/DC converter without some pre-fabbed chip or module meant for that purpose. The dsPICs are used a lot for power converter 'brains'.
Any links or suggestions? The only bucks I've "designed" are using national semiconductors web bench, and they don't seem to have a solution for what I need.
As loathe as I am to throw NS business, you could probably use a 400V PNP or P-FET as the power pass device bucking the main DC input, and use a switcher IC to drive an NPN with it's emitter grounded whose collector pulls down on the P buck transistor. There are probably a bunch of generic switcher controllers you could use, you will have to create a lower voltage rail like 20V to run the IC maybe with a power resistor and zener down from 150V. That bias voltage rail can be poorly regulated, doesn't matter.