A voltage proportional to absolute temperature (VPTAT) can be used, e.g., in a temperature sensor as well as in a bandgap voltage reference circuit. A bandgap voltage reference circuit can be used, e.g., to provide a substantially constant reference voltage for a circuit that operates in an environment where the temperature fluctuates. A bandgap voltage reference circuit typically adds a voltage complimentary to absolute temperature (VCTAT) to a voltage proportional to absolute temperature (VPTAT) to produce a bandgap reference output voltage (VGO). The VCTAT is typically a simple diode voltage, also referred to as a base-to-emitter voltage drop, forward voltage drop, base-emitter voltage, or simply VBE. Such a diode voltage is typically provided by a diode connected transistor (i.e., a BJT transistor having its base and collector connected together). The VPTAT can be derived from one or more VBE, where ΔVBE (delta VBE) is the difference between the VBEs of BJT transistors having different emitter areas and/or currents, and thus, operating at different current densities. However, because BJT transistors age in a generally random manner, the VPTAT (as well as the VCTAT) will tend to drift over time, which will adversely affect a temperature sensor and/or a bandgap voltage reference circuit that relies on the accuracy of the VPTAT (and the accuracy of the VCTAT in the case of a bandgap voltage reference circuit). It is desirable to reduce such drift. Additionally, VPTAT and bandgap voltage reference circuits generate noise, a strong component of which is 1/f noise (sometimes referred to as flicker noise), which is related to the base current. It is desirable to reduce 1/f noise.