Patent ID: 8446140

Claim:
A bandgap voltage reference circuit to produce a bandgap voltage output (VGO), comprising: a group of X current sources each of which produces a corresponding current that is substantially equal to the currents produced by the other current sources within the group, where X≧3; a plurality of circuit branches of the bandgap voltage reference circuit including first and second circuit branches used to produce a voltage proportional to absolute temperature (VPTAT), and a third circuit branch used to produce a voltage complementary to absolute temperature (VCTAT), wherein the VPTAT and the VCTAT are collectively used to produce the bandgap voltage output (VGO), and wherein each of the first, second and third circuit branches includes one or more transistors that produce base-to-emitter voltage drops used to produce the VPTAT or the VCTAT; and a plurality of switches adapted to selectively rotate each of the current sources into and out of each of the first, second and third circuit branches to thereby selectively change over time which of the current sources provide current to the first circuit branch, which of the current sources provide current to the second circuit branch, and which of the current sources provide current to the third circuit branch; wherein the current sources are separate components from the switches and separate components from the transistors that produce the base-to-emitter voltage drops.