Patent ID: 8324881

Claim:
A band gap voltage reference circuit comprising: a band gap reference generator circuit including: current source circuitry for supplying a first current to a first conductor and a second current to a second conductor, wherein the current source circuitry includes a plurality of unit current sources each for delivering a unit current; a plurality of diodes each having a cathode terminal coupled to a first reference voltage, a first group of switches for selectively coupling the first conductor to anode terminals of the diodes, respectively, in response to a first digital control signal to cause the first current to flow into a selected diode, a second group of switches for selectively coupling the second conductor to anode terminals of the diodes which are not selectively coupled to the first conductor in response to the first digital control signal to cause the second current to flow into and be shared among the diodes which are not selectively coupled to the first conductor, wherein the first control signal has values which cause the diodes to be successively coupled to the first conductor so that the first current causes the diodes, respectively, to produce corresponding relatively large VBE voltages on the first conductor and the second current causes the successively coupled diodes not coupled to the first conductor to produce corresponding relatively small VBE voltages on the second conductor, a difference between each relatively large VBE voltage and a corresponding relatively small VBE voltage being equal to a corresponding ΔVBE voltage; a third group of switches for selectively coupling the first conductor to the unit current sources, respectively, in response to a second digital control signal to produce the first current; and a fourth group of switches for selectively coupling the second conductor to the unit current sources which are not selectively coupled to the first conductor in response to the second digital control signal to produce the second current; sampling circuitry for sampling the relatively large VBE voltages and the relatively low VBE voltages to generate differential band gap charges; and averaging circuitry coupled by first and second output conductors of the sampling circuitry to receive the differential band gap charges for averaging successive differential band gap charges to provide a stable band gap reference voltage.