Patent ID: 6828847
Filing Date: 2004-12-07
Classification: G05F

Abstract:
A bandgap voltage reference circuit for providing a temperature stable voltage reference with TlnT temperature curvature correction, the bandgap voltage reference circuit comprising at least one first transistor and at least one second transistor supplied with respective PTAT currents, the at least one second transistor being operable at a current density lower than the current density at which the at least one first transistor is operable, and co-operating with the at least one first transistor for developing a correcting PTAT voltage proportional to the difference in the base-emitter voltages of the first and second transistors for combining with an uncorrected transistor base-emitter CTAT voltage for producing the voltage reference, wherein a CTAT correcting current is supplied to one of the at least one second transistors along with the PTAT current for developing the correcting PTAT voltage with a curvature complementary to the TlnT temperature curvature of the uncorrected transistor base-emitter CTAT voltage, so that when the correcting PTAT voltage is combined with the uncorrected transistor base-emitter CTAT voltage, the voltage reference produced is temperature stable and TlnT temperature curvature corrected.