A 10ppm/°C 1.8V piecewise curvature-corrected bandgap reference in 0.5µm CMOS

Abstract

A piecewise curvature-corrected bandgap reference (BGR) is presented. It features in utilizing a piecewise curvature-corrected current generator and an operational amplifier biased by a current proportional to absolute temperature (PTAT) to a conventional first order BGR. The piecewise current corrects the nonlinear temperature term of the first-order BGR in the higher temperature range (TR). The PTAT biased current compensates the trans-conductance degradation of the operational amplifier with temperature. Measured result shows that the proposed BGR achieves temperature coefficient of 10ppm/°C in the TR of 10–125°C, line regulation of 1.8mV/V in the supply range of 1.7–4.0V, power supply rejection(PSR) of −48dB. It is fabricated in CSMC0.5µm mixed signal CMOS process with chip area of 400×300µm and power consumption of 48µW.