SFS302405B SFS 30W Isolated DC-DC Converter Surface Mount, Voltage in 18. The SFS Series of isolated DC-DC converters have been designed to be very compact: ideally suited for applications where space is at a premium. They offer a wide range of power ratings and output voltages making them extremely versatile. Additional feature include remote sensing, remote on/off and alarm. The units also offer overcurrent and overvoltage protection.