2-Terminal floating bandgap voltage reference

A circuit is described for a 2-terminal bandgap voltage reference that is functionally equivalent to a very-low-impedance low-noise 1.2 V Zener diode. The circuit is all-npn, it is simple (it closely resembles five common-emitter stages connected in cascade), yet it is fully compensated for base-current and collector-voltage variations. Being 2-terminal, the circuit can be floated to provide a constant voltage difference between any two nodes in an integrated circuit (IC).