A superior-order curvature corrected bandgap reference with less sensitivity of mismatch

Abstract

A superior-order curvature corrected bandgap reference (BGR) is proposed. The BGR features itself by adding only an extra NMOS transistor to a first-order BGR. The extra transistor generates a piecewise nonlinear corrected current to reduce its temperature coefficient (TC) and forms a negative feedback to decrease the variation of offset and TC caused by mismatch. Measurement result shows the proposed BGR achieves most optimal TC of 2.8ppm/°C in the temperature range of -40∼125°C. The variation of offset and TC among different samples are reduced by the negative feedback effectively.