A bandgap reference includes a current source providing a current that is
proportional to the sum of a first voltage having a
positive-to-absolute-temperature (PTAT) temperature dependency and a
second voltage having a complementary-to-absolute-temperature (CTAT)
dependency. The bandgap reference further includes a variable resistor
comprising a fixed resistor that may be selectively combined with one or
more of a plurality of selectable resistors, wherein the first voltage is
inversely proportional to the resistance of the variable resistor.