The use of a positive-to-negative voltage converter to achieve stable outputs even with a widely varying input is described.
Synchronous step-down converter
An obvious application of a positive-to-negative converter is generating a negative voltage output from a positive input. However, a not-so-obvious use is to produce a stable output voltage in an application that has a widely varying input. For example, a converter in a battery-powered device, which has an inherently variable input voltage, can produce a stable output voltage even if input voltage falls below the absolute value ...