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 of the output voltage. However, an
obvious drawback is reverse polarity, which can be easily
overcome in this application. The supplied circuitry can use
the negative output as the system ground and the negative
battery terminal as the “positive” voltage source.
Download the full Design Note as a PDF.