LM2575 is a low efficiency device. So if efficiency is not your concern, you can go for it. There are other options as well
LM2596 is a similiar device with some improvement in efficiency.
You can use a current mode regulator like SG3842 with an external MOSFET to get better efficiency.
For best result, as eem2am said, use a synchronous buck since you have a low duty cycle and the flyback diode in will be conducting most of the time if you use non-synch
Hi guys, i am new to this forum and most others, so i must say another great forum to help others.
I also have a need for a switchmode converter from 48V. i need a diagram for a 48V (max 60V fully charged) to +12V and - 12V Isolated switching converter. It is to be used with my solar and wind power MPPT controllers. The current required is only about 100mA max, as it only supplies 6 op amps. It has to be isolated to avoid shorts and ground loops. So i only need a diagram for the power supply section like Alzomor, but space is not so much of a problem. I am OK with linear supplies but not switchers. I could probably tap +12V off the +48V battery but of course not the -12V. I could get away with -5V also. I have seen the diagram posted using LM2575, but this is not isolated.