A bandgap reference circuit includes a first bipolar junction transistor (BJT) in series with a first current generator, the first BJT and the first current generator configured to produce a first proportional to absolute temperature (PTAT) signal. The circuit also includes a second BJT in series with a second current generator, the second BJT and the second current generator configured to produce a second PTAT signal. The bandgap reference circuit maintains a current through at least one of the first BJT or the second BJT within a constant ideality factor region of the at least one of the first BJT or the second BJT.