A 1.2-V Piecewise Curvature-Corrected Bandgap Reference in 0.5 $\mu$ m CMOS Process

A 1.2-V piecewise curvature-corrected CMOS bandgap reference (BGR) is proposed. It features in utilizing piecewise nonlinear curvature-corrected current and rail-to-rail operational amplifier to a conventional first-order current-mode BGR. The corrected current is zero, exponential with temperature and proportional to the squared temperature in the lower, middle and higher temperature range (TR). The rail-to-rail operational amplifier biased by a current proportional to absolute temperature (PTAT) helps to provide negative feedback for the proposed BGR. Measured results indicate that the proposed BGR achieves temperature coefficient (TC) of 8.9 ppm/°C in the TR of -40°C-110°C without trimming, power supply rejection (PSR) of - 58 dB and line regulation of 2.4 mV/V in the supply range of 1.2-3.2 V. It is fabricated in CSMC 0.5-μ m mixed-signal CMOS process with power consumption of 48 μW and effective chip area of 0.1 mm² .