I am making an intermittent load full bridge with SiC FETs. The intermittent load demands isolated DC-DC supplies for the high side FETs.
My question is, if I have +15 and -5 available elsewhere in my circuit is it preferable to isolate the entire switching circuit, FETs and drivers, or just do a good job with the ground planes throughout the entire board. I have always used the boot strap type drive for the high side FETs and successfully included the low side supplies from the rest of the circuitry. Is isolating all the supplies for the FET drives the preferred approach? Are there any recommended tricks or cautions to this?
