A High-Precision Resistor-Less CMOS Compensated Bandgap Reference Based on Successive Voltage-Step Compensation

A curvature-compensated resistor-less bandgap reference (BGR), which is fabricated in 0.5-mu m CMOS process, is proposed in this paper. The BGR utilizes successive voltage-step compensation to produce a temperature-insensitive voltage reference (VR), including one Delta V-GS step for first-order compensation and another one for higher order curvature correction. Moreover, a supply noise bypassing technique is adopted to achieve good power supply rejection performance up to high frequency. Experimental results demonstrate that this BGR is able to produce a VR of 1.196 V with a temperature coefficient of 3.98 ppm/degrees C at 3.6-V supply voltage. A power-supply noise attenuation of -84 dB@100 Hz and -37 dB@100 kHz are easily achieved, and the line regulation is better than 0.19 mV/V when supply voltage varies from 2.1 to 5 V. The proposed reference occupies an active area of 356 mu m x 150 mu m and consumes a quiescent current of 38 mu A.