The high input voltage non-isolated DC-DC converters offer unique solutions for converting high-powered, variable voltages to a wide range of output voltages. The converter is a non-isolated buck-boost regulator, which employs synchronous rectification to achieve extremely high conversion efficiency. These products are suitable for use in Intermediate Bus Architectures, or to provide a regulated output voltage from a variable voltage source such as a battery. They can be configured to ‘buck’ the input voltage down or ‘boost’ the input voltage up with a single external setpoint resistor.