When generating a negative output voltage from a positive input voltage, use the buck (step down) regulator that is already available. This step-by-step procedure helps guide the user through designing an inverting power supply using a wide input voltage family of SWIFT DC/DC converters. Applying duality to a buck regulator, allows the user to derive an inverting (buck-boost) regulator as shown in the References (1 and 2) at the end of this application report.