An auto voltage sense circuit uses voltage controlled current sources to
generate a desired reference voltage level that closely tracks the
variations and changes of a first voltage level and a second voltage
level. The auto voltage sensing circuit includes a first voltage
controlled current source operable to receive the first voltage level to
generate a reference current that is proportional to the first voltage
level. The auto voltage sensing circuit also includes a second voltage
controlled current source operable to receive the second voltage level
and the reference voltage to generate an output current that is
proportional to the difference between the second voltage level and the
reference voltage. The reference voltage causes the output current to be
approximately equal to the reference current so as to generate a
reference voltage that is proportional to the difference between the
second voltage level and the first voltage level.