3rd order curvature corrected bandgap cell

A curvature corrected bandgap voltage reference cell is described which exhibits a compensation of temperature for powers of T up to 3. The curvature correction is fully implemented with the addition of only two passive resistors to a standard Brokaw bandgap cell. Aside from the improved linearity a benefit over prior art is a fivefold decrease in sensitivity to processing variations on the diffused resistor. Theoretical performance of 0.02 ppm/C can be simulated, but limitations of real circuit devices (in particular the thermal hysteresis of transistors) limit the actual performance of the circuit to around 1 ppm/C typical