Patent ID: 8704589

Claim:
A reference voltage circuit comprising: first and second base-emitter pairs; a feedback loop configured to drive a current through each of the first and second base-emitter pairs; a plurality of switches coupled between the feedback loop and the first and second base-emitter pairs, including first and second switches controlled by a first control signal and third and fourth switches controlled by a second control signal complementary to the first control signal; and a network of resistors coupled between the feedback loop and the plurality of switches, including first and second resistors for setting a gain when the first control signal is active and third and fourth resistors for setting the gain when the second control signal is active, wherein the first and second resistors have resistances approximately equal to the resistances of the third and fourth resistors, respectively; wherein the voltage reference circuit is configured to generate a reference voltage by summing the voltage across the first base-emitter pair with a difference voltage multiplied by a factor of K, and wherein the voltage reference circuit is configured to toggle the switches so that during a first time period defined by the first control signal, the difference voltage is the voltage across the first base-emitter pair minus the voltage across the second base-emitter pair, and during a second time period defined by the second control signal, the difference voltage is the voltage across the second base-emitter pair minus the voltage across the first base-emitter pair.