Patent ID: 7880533
Filing Date: 2011-02-01
Classification: G05F

Abstract:
1. A bandgap voltage reference circuit comprising: an amplifier having an inverting input, a non-inverting input and an output, first and second bipolar transistors operating at different collector current densities each associated with a corresponding one of the inverting and non-inverting inputs of the amplifier, a first load MOS transistor of a first aspect ratio being driven by the amplifier to operate in the triode region with a corresponding drain-source resistance r a second load MOS transistor of the same type as the first load MOS transistor and with a second aspect ratio different than the first aspect ratio, such that the PTAT voltage developed across the first load MOS transistor is reflected with a gain across the second load MOS transistor, the gain voltage being PTAT from drain to source of the second load MOS transistor, from which a reference voltage is derived; and a cascoded MOS device of a second aspect ratio operably coupled to the first load MOS transistor and being driven by the amplifier to operate in the triode region.