Patent ID: 9740229
Date: 2017-08-22
CPC Classifications: G05F

Claim:
1. A curvature-corrected bandgap reference, comprising: a first current source proportional to absolute temperature; a first resistor which conducts a first current from the first current source to generate a proportional to absolute temperature voltage; the curvature-corrected bandgap reference further comprising a first BJT device including a first base terminal coupled to an output node and a first emitter terminal, wherein the first BJT device operates at a first current density that is substantially proportional to absolute temperature; a second BJT device including a second base terminal coupled to a second emitter terminal, wherein the second BJT device operates at a second current density that is substantially independent of temperature; a correction voltage proportional to a voltage difference of the first and second emitter terminals, wherein the correction voltage substantially cancels a curvature of a reference voltage; a circuit operable to force the second current density to be substantially proportional to the reference voltage; wherein the circuit further includes a resistor coupled to the reference voltage; a current mirror coupled to the resistor and to a collector of the second BJT device; and a base current compensation block coupled to a collector of the first BJT device and to the collector of the second BJT device, the base current compensation block diverts a current nominally equal to base currents of the first and second BJT devices such that the first and second current densities are nominally independent of the base currents of the first and second BJT devices, wherein accuracy of curvature correction is thereby improved.